Cell Markers and Genetic Abnormalities for Hodgkin and Non-Hodgkin Lymphomas

HODGKIN LYMPHOMA

Hodgkin lymphoma with a Reed-Sternberg cell

In the center of the photomicrograph is a classic Reed-Sternberg cell,a binucleate cell with large “owl’s eyes” eosinophilic nucleoli.

Hodgkin lymphoma, nodular sclerosis variant

Note the nodules of lymphocytes and other hematopoietic cells divided by broad fibrous septae.

Hodgkin lymphoma, mixed cellularity variant

Note the Reed-Sternberg cell (arrowhead). The other cell types in this image are reactive (only the Reed-Sternberg cell is neoplastic) and include neutrophils, lymphocytes, and, prominently in this image,eosinophils.

NON-HODGKIN LYMPHOMA

Spleen, non-Hodgkin lymphoma. This spleen exhibits uniform multicentric involvement of the white pulp by a malignant lymphoma. These changes contribute to generalized splenomegaly.

Follicular lymphoma

This lymph node exhibits the characteristic low power features of follicular lymphoma, tightly packed lymphoid follicles of approximately equal size.

Follicular lymphoma involves this hilar lymph node. The black material (arrow) represents normal lymphoid parenchyma with anthracotic pigment displaced 

to one side by the expanding tan lymphomatous process.

Diffuse large B-cell lymphoma

The photomicrograph shows a sheet of monotonous large neoplastic cells with prominent nucleoli.

Burkitt lymphoma

This photomicrograph illustrates the characteristic low power features of Burkitt lymphoma, a sheet of neoplastic cells interspersed with punctate clearings (“starry sky pattern”). The punctate clearings are macrophages engulfing cellular debris. Burkitt lymphoma is an aggressive rapidly growingneoplasm with abundant cellular turnover, hence the presence of the macrophages

Hairy cell leukemia

In the upper left corner is a single neoplastic lymphoid cell. Note the fine hair-like projections from its surface.


General Category Specific Name of Genetic Abnormality of Lymphoma Lymphoma Cell Markers (if associated with one)

Hodgkin lymphoma 

• NS-HL CD 15, 30+ EBV
• MC-HL CD 15, 30+ EBV+
• LP-HL CD 20, EMA + CD 15, 30

Non-Hodgkin lymphoma 

• Follicular lymphoma CD 19,20, and 10+ t(14;18)–bcl-2 surface Ig, bcl-2+ 3q27 abnormalities

• Diffuse large B-cell CD 19,20, and 79a+ t(14;18)–bcl-2 lymphoma Surface Ig+ 3q27 abnormalities

• Burkitt lymphoma CD 10, 19 and 20+ t(8;14)–MYC Bcl-6 and surface Ig+

• Precursor T-cell lymphoblastic Tdt, CD 2 and 7+ Abnormalities of TAL1 leukemia/lymphoma

• Mantle cell lymphoma CD 19,20 and 5+ t(11;14)–cyclin D1 Surface Ig+ CD23

• MALToma CD19, 20 t(1;14)–bcl-10 t(11;18)

• Hairy cell leukemia CD 19, 20, 11c and 103 TRAP+

NS-HL, nodular sclerosis Hodgkin lymphoma; EBV, Epstein-Barr virus; EMA, epithelial membrane antigen; MC-HL, mixed cellularity Hodgkin lymphoma; LPHL,
lymphocyte predominant Hodgkin lymphoma; TRAP, tartrate-resistant acid phosphatase.

Developmental dysplasia of the hip (DDH)

Definition

• A spectrum of disorders ranging from complete dislocation of the femoral head to a reduced hip joint with acetabular dysplasia

Types:

1. Complete hip dislocation.

2. Partial hip subluxation.

3. Hip dysplasia (incomplete development).

Risk factors:

• family history - may reflect laxity of ligaments
• Race- common in white 
• Breech  presentation - Exaggerated positioning in acute flexion and adduction in utero may occur
• Female sex - the presence of maternal relaxin in the fetal circulatory system
• large fetal size 
• First born child

Galeazzi's test

• With the child is lying on a flat surface, flex the hips and knees so the heels rest flat on the table, just distal to the buttock . 
• A dislocated hip is signaled by relative shortening of the thigh compared with the normal leg, as shown by the difference in knee height level. 
• This test is almost always useless in children under 1 year of age and is negative if dislocation is bilateral.

Barlow's test

• This is a provocative test that picks up an unstable but located hip; it is unsuitable for a dislocated hip. 
• Thighs are gently grasped in the hand, with the thumb at the lesser trochanter and fingers at the greater trochanter . The hip is adducted slightly and gently pushed posteriorly with the palm. 
• Detection of "pistoning," or the sensation of the femoral head subluxating over the posterior rim of the acetabulum, is a positive finding.

Ortolani's test:

• This test detects hips that are already dislocated. 
• The flexed limb is grasped as in Barlow's test. The hip is abducted while the femur is gently lifted with the fingers at the greater trochanter. 
• In a positive test, there will be a sensation of the hip reducing back into the acetabulum. 

Clinical Manifestations

In newborn:

• We can diagnose DDH in this period by positive Ortolani’s test or Barlow’s test.
• Asymmetry of the skin fold may help, but its not specific. 
• Shortening of the limb at this age doesn’t exist.
• We cant use X-rays because the acetabulum and proximal femur are cartilaginous and wont be shown on X-ray.
• USG is the best method to Dx.

In the early childhood:

• Parents notice asymmetry of creases of groin, limitation of movement of affected hip or click every time hip is moved

In older children:

• Complaints of limping, waddling gait (bilateral DDH), Trendelenburg’s gait (unilateral DDH), lumbar lordosis, limitation of hip abduction, etc…

X-ray

Von Rosen view:

hips abducted 45º & medially rotated.

Anteroposterior.

We draw a line through the central axis of the femoral shaft.

        in normal hip ( ossific nucleus )will be inside the acetabulum.

        in dislocated hip it will be above acetabulum.

Delayed development of ossific nucleus / smaller

Horizontal line of Hilgenreiner:

   drawn between upper ends of tri-radiate cartilage of the acetabulum.

Vertical line of Perkins:

  drawn from the lateral edge of the acetabulum vertical to horizontal line.

4 quadrants:

Normal hip: the ossification center of the femoral hip lower medial quadrant.

Dislocated hip: upper lateral quadrant.

Acetabular index:

    angle between horizontal line of Hilgenreiner and the line between the two edges of the acetabulum.

    normal hip 20º-300 

    dilocated or dysplastic hip ≥ 30º

Shenton’s line:

    semicircle between femoral neck and upper arm of obturator foramen, in dislocated hip this line is broken.

Treatment:

The earlier the better. 

Exact treatment depends on patient age at presentation and degree of involvement

Goal is to:

1.Flex and abduct hips.

2.Reduce femoral head and maintaining it.

Reduction can be achieved by closed manipulation , traction followed by closed reduction and opened reduction  

 maintenance can be done using plaster cast(frog leg or Batchelor) or splint (von Rosen’s splint)

• Acetabular reconstruction procedure
• Salter’s osteotomy
• Chiari’s pelvic displacement osteotomy 
• Pemberton’s pericapsular osteotomy

• From (0-6 months)  

A dislocated hip at this age may spontaneously reduce over 2-3 weeks if the hip is held in a position of flexion. 

Reduction by closed manipulation and maintained with plaster cast or splint

• From 6 months -2 year

Gentle closed reduction of the dislocation under a general anesthetic and maintenance of a located position for 2-3 months in a hip spica cast usually stabilize the joint

• From the age of 2-6 years:

open reduction with osteotomy

• 6-10 years

No treatment for bilateral
Open reduction with reconstruction for unilateral

• After 10 years

Only indication for treatemnt is pain. If only one hip affected total hip replacement may be done.

Pathogenesis of Disseminated Intravascular Coagulation (DIC)

• Consumptive Coagulopathy
• Widespread coagulation leading to thrombin formation all over body and consumption of all platelets and coagulation factors.
• Everything is consumed, and there are thrombi all over body.
• Bleeding and vessel occlusion at the same time

• Which LAB parameters will be abnormal???
• All that you can think of….
• Bleeding time, PT, aPTT, D-dimer, Fibrin Split Products

CORONARY ARTERIES

From: Ascending aorta
To: Myocardium 

Right coronary artery. Originates from the anterior (new nomenclature: right) aortic sinus. It passes anteriorly between the pulmonary trunk and the right auricle to reach the atrioventricular sulcus in which it runs down the anterior surface of the right cardiac border and then onto the inferior surface of the heart. It terminates at the junction of the atrioventricular sulcus and the posterior interventricular groove by anastomosing with the circumflex branch of the left coronary artery and giving off the posterior interventricular (posterior descending) artery. It supplies the right atrium and part of the left atrium, the sinuatrial node in 60% of cases, the right ventricle, the posterior part of the inter- ventricular septum and the atrioventricular node in 80% of cases.
Left coronary artery. Arises from the left posterior (new nomenclature: left) aortic sinus. It passes laterally, posterior to the pulmonary trunk and anterior to the left auricle to reach the atrioventricular groove where it divides into an anterior interventricular (formally left anterior descending) artery and circumflex branches.
The circumflex artery runs in the atrio- ventricular sulcus around the left border of the heart to anastornose with the right coronary artery. The anterior inter-ventricular artery descends on the anterior surface of the heart in the anterior interventricular groove and around the apex of the heart into the posterior interven-
tricular groove where it anastomoses with the posterior interventricular branch of the right coronary artery. The left coronary artery supplies the left atrium, left ventricle, anterior interventricular septum, sinuatrial
node in 40% of cases and the atrioven- tricular node in 20%.
Dominance. In approximately 10% of hearts the posterior interventricular artery arises from the circumflex artery (left coronary) and then most of the left ventricle and interventricular septum are supplied by the
left coronary artery. The heart is said to have left cardiac dominance.

DISEASES WITH THEIR ENZYME DEFICIENCIES

Criggler-Najjar - UDP-glucuronyl transferase
Von-Gierke’s - Glucose -6- phosphatase
Pompe’s - Acid maltase( Acid α glucosidase)
Mc Ardle’s - Muscle glycogen phosphorylase
Tarui’s disease - Muscle phosphorylase
Niemann-Pick’s - Sphingomyelinase
Farber’s - Ceramidase
Gaucher’s - β-glucosidase
Krabbe’s - β-galactosidase
Tay-Sach’s - Hexosaminidase-A
Phenylketonuria - Phenylalanine hydroxylase
Alkaptonuria - Homogentisate oxidase
Albinism - Tyrosinase
Fabry’s - α-galactosidase
Lesch-Nyhan syndrome - HGPRT
Sandhoff - Hexosaminidase-β
Xeroderma pigmentosum - DNA exinuclease
Sudden infant death syndrome - Medium chain acyl CoA dehydrogenase
Maple syrup urine - Branched chain α-ketoacid dehydrogenase
Acute Intermittent Porphyria- Uroporphyrinogen-1 synthase
Maple syrup urine disease - Alpha ketoacid decarboxylase
Hereditary fructose intolerance Aldolase b
Fructosuria - Fructokinase b
Galctosemia - Galactose-1-phosphate uridyl transferase

Important presentation about Thalassemia (Microcytic Anemia)

• Definition: hereditary underproduction of either the alpha or beta globin chains of the hemoglobin A  resulting in a  microcytic anemia.
• Beta thalassemias are due to mutations in the HBB gene on chromosome 11.
• The α thalassemias involve the genes HBA1 and HBA2 on chromosome 16.

Beta- Thalassemia

• The β-globin mutations associated with β-thalassemia fall into two categories: 
• (1) β0, in which no β-globin chains are produced; and 
• (2) β+, in which there is reduced (but detectable) β-globin synthesis
• Individuals inheriting one abnormal allele have thalassemia minor or thalassemia trait, which is asymptomatic or mildly symptomatic. 
• Most individuals inheriting any two β0 and β+ alleles have β-thalassemia major; 
• occasionally, individuals inheriting two β+ alleles have a milder disease termed β-thalassemia intermedia.

Alpha-Thalassemias

• alpha- thalassemias result in decreased alpha-globin production, therefore fewer alpha-globin chains are produced, resulting in an excess of β chains in adults and excess γ chains in newborns.The excess β chains form unstable tetramers (called Hemoglobin H or HbH of 4 beta chains) which have abnormal . The severity of the alpha- thalassemias is correlated with the number of affected alpha-globin genes.  
•  alpha0 thalassaemias, where there is lots of gama4 but no alpha-globins at all (referred to as Hb Barts), often result in still birth.

• The most severe form of alpha thalassemia major causes stillbirth.
• Other symptoms can include:
• Bone deformities in the face
• Fatigue
• Growth failure
• Shortness of breath
• splenomegaly

Diagnostic features of beta-thalassaemia

Dx

• A physical exam may reveal a swollen (enlarged) spleen.
• Blood test:
• Red blood cells will appear small and abnormally shaped when looked at under a microscope.
• A complete blood count (CBC) reveals anemia.
• A test called hemoglobin electrophoresis shows the presence of an abnormal form of hemoglobin

Rx

• Treatment for thalassemia major often involves regular blood transfusions and folate supplements.
• If you receive blood transfusions, you should not take iron supplements. Doing so can cause a high amount of iron to build up in the body, which can be harmful.
• Persons who receive significant numbers of blood transfusions need a treatment called chelation therapy to remove excess iron from the body.
• Bone marrow transplant may help treat the disease in some patients, especially children.
• Hydrops fetalis: none available 
• Haemoglobin H: no specific therapy required; avoid iron therapy; folic acid if necessary 

TREATMENT OF BETA-THALASSAEMIA MAJOR

Most common conditions in medicine

1. Most common aortic branch involved in Takayasu arteritis : Left subclavian
2. Most common cause of respiratory distress in newborn : Transient tachypnea of the newborn
3. Most common location to see Asbestosis sequale : Posterior lower lobes.
4. Most common karyotype / chromosomal abnormality in USA : Down’s syndrome
5. Most common osseous lymphoma, primary and secondary : Diffuse large B-cell lymphoma
6. Most common primary malignant orbital tumor in childhood : Rhabdomyosarcoma
7. Most common type of fluid collection in scrotum : Hydrocele
8. Most common type of liposarcoma to affect children : Myxoid liposarcoma
9. Most common abdominal emergency of early childhood : Intussusception.
10. Most common acetabular fracture : Posterior acetabulum.
11. Most common affected bowel segment in TB : Ileocecal area.
12. Most common affected joint in gout : First MTP.
13. Most common AIDS-related neoplasm : Kaposi Sarcoma
14. Most common allergic aspergillosis syndrome : Allergic bronchopulmonary aspergillosis.
15. Most common anatomic variant of pancreas : Pancreas divisum
16. Most common anomalous course of RCA : Interarterial
17. Most common appearance of Legionella at the peak of the disease : Bilateral airspace consolidation.
18. Most common assoc. w/ Fx of great toe distal phalanx with physeal involvement :Osteomyelitis.
19. Most common associated anomaly with coarctation : Bicuspid valve.
20. Most common association of PAPVR : Sinus venosus type ASD.
21. Most common association with small left colon syndrome : Maternal DM
22. Most common bacterial cause of mesenteric adenitis : Yersinia enterocolitica.
23. Most common benign cardiac rhythm abnormality : PAC
24. Most common benign cartilage-containing tumor : Osteochondroma
25. Most common benign growth of the skeleton : Osteochondroma
26. Most common benign hepatic lesion : Hemangioma
27. Most common benign hepatic tumor during fist 6 mo. of life : Infantile Hemangioendothelioma
28. Most common benign intraconal tumor of the orbit in adults : Cavernous hemangiomas.
29. Most common benign masses caused by asbestos exposure : Atelectatic Asbestos Pseudotumor
30. Most common benign mesenchymal tumor of kidney : AML
31. Most common benign mucosal tumor of the esophagus : Papilloma
32. Most common benign nasopharyngeal tumor : Juvenile angiofibroma.
33. Most common benign orbital tumor in childhood : Dermoid Cyst of Orbit
34. Most common benign ovarian neoplasm in young and middle-aged women (less than 45 years) :Mature teratoma
35. Most common benign radiation-induced tumor of the musculoskeletal system : Osteochondroma
36. Most common benign rib lesion in an adult : Fibrous dysplasia.
37. Most common benign soft-tissue tumor of the foot : Plantar fibromatosis
38. Most common benign soft-tissue tumor of vascular origin : Hemangioma
39. Most common benign solid tumor in women of childbearing age : Fibroadenoma
40. Most common benign testicular mass : Simple cyst
41. Most common benign tumor of spleen : Hemangioma
42. Most common benign tumor of the larynx : Squamous papilloma
43. Most common benign tumor of the lung : Hamartoma
44. Most common benign tumor of the small bowel : GIST
45. Most common benign vascular gastric tumor : Glomus tumor of stomach.
46. Most common bilateral testicular tumor : Lymphoma
47. Most common biliary complication s/p lap. cholecystectomy : Bile duct leak from cystic duct stump.
48. Most common biliary complication s/p liver transplantation : Obstruction/stenosis at anastomosis.
49. Most common bladder neoplasm in children younger than 10 years : Rhabdomyosarcoma
50. Most common bone to develop an osteochondroma : Femur (tibia second most common)
51. Most common brain anomaly on prenatal sonograms : Isolated Mild Ventriculomegaly
52. Most common breast tumor under age 25 years : Fibroadenoma
53. Most common cardiac manifestation of Systemic Lupus Erythematous : Pericarditis
54. Most common cardiac tumor in children : Rhabdomyoma.
55. Most common cardiac valvular tumor : Papillary fibroelastoma
56. Most common carpal dislocation : Transscaphoid perilunate dislocation.
57. Most common causative organism of acute pyogenic meningitis in adults : Strep. pneumoniae
58. Most common causative organism of neonatal pyogenic meningitis : E. coli
59. Most common cause for failure of dialysis graft : Fibrointimal hyperplasia : venous outflow stenosis.
60. Most common cause for late failure in lung transplant patient : Bronchiolitis obliterans
61. Most common cause for pulmonary edema : Left-sided heart disease
62. Most common cause non iatrogenic cause of small bowel obstruction : Hernia
63. Most common cause of a large choroid plexus cyst : Trisomy 18.
64. Most common cause of a large pleural fluid collection in the newborn period : Chylothorax
65. Most common cause of acute renal failure in children requiring dialysis : HUS
66. Most common cause of acute testicular pain in postpubertal male : Acute epididymitis
67. Most common cause of acute testicular pain in prepubertal male : Torsion
68. Most common cause of AIDS cholangiopathy : Cryptosporidium
69. Most common cause of an echogenic renal mass in a 3-month-old : Mesoblastic nephroma.
70. Most common cause of an intraorbital mass lesion in adult : Pseudotumor of Orbit
71. Most common cause of AS in Western world : Degenerative disease
72. Most common cause of bilateral breast edema : CHF.
73. Most common cause of bilateral echogenic renal cortex : Chronic glomerulonephritis.
74. Most common cause of biliary obstruction : Choledocholithiasis
75. Most common cause of bleeding between menstrual cycles : Endometrial hyperplasia.
76. Most common cause of bronchopneumonia : Staphylococcal
77. Most common cause of cancer deaths in males and females : Bronchogenic Carcinoma
78. Most common cause of cause of infectious esophagitis : Candida Esophagitis
79. Most common cause of cavitary (necrotic) pneumonia in a child : Strep pneum.
80. Most common cause of Charcot joints : Diabetes mellitus
81. Most common cause of CHF in a child : ALCAPA / aberrant left coronary artery
82. Most common cause of CHF in a neonate : Hypoplastic Left Heart.
83. Most common cause of chronic hydronephrosis in renal transplant : UV anastomosis stricture.
84. Most common cause of colonic obstruction in adults : Malignancy
85. Most common cause of colonic obstruction in the infant : Meconium plug syndrome in CF patients
86. Most common cause of colovesical fistula : Diverticulitis
87. Most common cause of congenital CNS infection : CMV.
88. Most common cause of congenital duodenal obstruction : Duodenal atresia.
89. Most common cause of congenital sensorineural hearing loss : Giant vestibular aqueduct syndrome
90. Most common cause of cord ischemia : Thromboembolic disease
91. Most common cause of coronary artery aneurysm in USA : Atherosclerosis
92. Most common cause of coronary artery aneurysm Worldwide : Kawasaki
93. Most common cause of cyanosis in a child : Tetralogy of Fallot
94. Most common cause of cyanosis in newborn Transposition of great vessels
95. Most common cause of death in a severe pelvic fracture : Hemorrhage.
96. Most common cause of death in Ataxia –Telangiectasia : Respiratory failure.
97. Most common cause of death in Jeune syndrome : Respiratory failure
98. Most common cause of drop mets : Medulloblastoma
99. Most common cause of dwarfism : Achondroplasia
100. Most common cause of echogenic renal pyramids in children : Furosemide
101. Most common cause of ejaculatory duct obstruction : Mullerian duct cyst ?
102. Most common cause of endometriosis in girls less than 16 years of age : Obstructive müllerian duct anomalies
103. Most common cause of end-stage renal disease : Diabetic Nephropathy
104. Most common cause of epididymitis in males aged 15 to 35 years : Sexually transmitted diseases
105. Most common cause of esophageal rupture : Iatrogenic
106. Most common cause of exocrine pancreatic insufficiency in patients less than 30 years of age : CF
107. Most common cause of facial hemipalsy : Bell palsy
108. Most common cause of false-positive V/Q scan for acute PE : Previous pulmonary embolism
109. Most common cause of fungal infection in AIDS patients : Cryptococcosis
110. Most common cause of gastrocolic fistula : Gastric ulcer.
111. Most common cause of heart failure in patients with COPD : Atherosclerotic heart disease
112. Most common cause of hemifacial spasticity is vertebrobasilar dolichoectasia.
113. Most common cause of hepatic calcifications : Infection
114. Most common cause of hydronephrosis in the newborn male : Ureteropelvic junction
115. Most common cause of hyperreflexive bladder : Spinal cord trauma
116. Most common cause of increased nuchal thickness : Downs syndrome
117. Most common cause of interstitial and airspace edema : CHF
118. Most common cause of intradiaphragmatic cyst :Extralobar sequestration
119. Most common cause of intraventricular hemorrhage :Disruption of the subependymal veins
120. Most common cause of intussusception in children >6 years : Lymphoma
121. Most common cause of large spherical pancreatic calcifications in children : Hereditary pancreatitis
122. Most common cause of left atrial dilatation : Mitral regurgitation.
123. Most common cause of leukokoria : Retinoblastoma.
124. Most common cause of liver metastasis : Colon.
125. Most common cause of lower extremity venous valve dysfunction : DVT.
126. Most common cause of lower GI bleeding : Diverticulosis.
127. Most common cause of malignancy of men in the world -- Bronchogenic Carcinoma
128. Most common cause of maternal peripartum death : Amniotic fluid embolism
129. Most common cause of membranous croup : Staph. Aureus.
130. Most common cause of microcolon: Meconium ileus.
131. Most common cause of mortality in ulcerative colitis : Toxic megacolon.
132. Most common cause of necrolytic migrating erythema : Glucagonoma
133. Most common cause of neonatal nasal obstruction : Choanal atresia.
134. Most common cause of Neonatal Pneumonia : Group B streptococcus.
135. Most common cause of neonatal respiratory distress in full term/postmature infants – Meconium aspiration
136. Most common cause of nephrocalcinosis in adults : Primary hyperparathyroidism
137. Most common cause of non-immune hydrops in USA : Cardiac anomaly
138. Most common cause of optic nerve enlargement : Optic nerve glioma
139. Most common cause of orbital calcifications : Retinoblastoma
140. Most common cause of orbital infection : Paranasal sinusitis
141. Most common cause of osteoblastic bone metastases in an adult female : Breast cancer
142. Most common cause of osteoblastic bone metastases in an adult male : Prostate cancer
143. Most common cause of osteolytic bone metastases in a child : Neuroblastoma
144. Most common cause of osteolytic bone metastases in an adult female : Breast cancer
145. Most common cause of osteolytic bone metastases in an adult male : Lung cancer
146. Most common cause of Osteomyelitis of spine : Penetrating direct trauma
147. Most common cause of pancreatic lipomatosis in children : CF
148. Most common cause of pleural eosinophilia : Air in the pleural space
149. Most common cause of pneumoperitoneum : Ruptured duodenal ulcer.
150. Most common cause of postpartum fever : Endometritis.
151. Most common cause of pseudomyxoma peritonei : Appendiceal mucinous adenocarcinoma
152. Most common cause of pseudoureterocele : Bladder tumor
153. Most common cause of pulmonary hypoplasia : Diaphragmatic hernia
154. Most common cause of pulmonary tumor embolus : Gastric carcinoma
155. Most common cause of recurrent hip disloc. s/p hip arthroplasty : Acetabular component malposition
156. Most common cause of reflux in child w/ non-duplicated collecting system: Short intramural ureter.
157. Most common cause of renal vein thrombosis in adults : Nephrotic syndrome
158. Most common cause of restrictive cardiomyopathy : Amyloid
159. Most common cause of round pneumonia in children : Streptococcus.
160. Most common cause of round pneumonia in children : Streptococcus
161. Most common cause of small bowel obstruction : Adhesions
162. Most common cause of squamous cell ca. in the renal pelvis : Chronic Infected stag horn calculus
163. Most common cause of stridor in neonate and young infant : Laryngomalacia
164. Most common cause of sudden cardiac death among young people Hypertrophic cardiomyopathy (HCM)
165. Most common cause of SVC syndrome : Bronchogenic carcinoma
166. Most common cause of testicular swelling : Hydrocele
167. Most common cause of the pulmonary-renal syndrome : Microscopic polyangitis.
168. Most common cause of the stripe sign on V/Q scan : COPD
169. Most common cause of thoracic outlet syndrome : Scalene anticus.
170. Most common cause of toxic mega colon : Pseudomembranous colitis.
171. Most common cause of tree in bud appearance on CT : Bronchiolitis
172. Most common cause of tricuspid stenosis : Rheumatic heart disease
173. Most common cause of unilateral diaphragmatic paralysis : Malignant invasion
174. Most common cause of unilateral nonperfused lung on V/Q scan : Bronchogenic carcinoma
175. Most common cause of unilateral pulmonary edema : Prolonged unilateral dependent positioning
176. Most common cause of urinary obstruction in boys : posterior urethral valves
177. Most common cause of valvular heart disease in the United States : Degenerative
178. Most common cause of vascular ring : Double arch.
179. Most common cause of vertebra plana in children : EG
180. Most common cause requiring bronchial artery embolization : CF
181. Most common cause worldwide for cholangiocarcinoma : Clonorchis sinensis infestation
182. Most common cerebellar neoplasm in children : Medulloblastoma
183. Most common cerebral mass lesion in AIDS : Toxoplasmosis
184. Most common chest radiograph finding seen in pts with an acute PE : Atelectasis
185. Most common chest x-ray abnormality in the ICU : Atelectasis
186. Most common child abuse facture : Diaphyseal fracture,
187. Most common collagen disorder for a pleural effusion : SLE
188. Most common colonic polyp : Hyperplastic polyp
189. Most common colonic site for lymphoma : Cecum
190. Most common complication of ERCP : Pancreatitis
191. Most common complication of popliteal artery aneurysm : Distal ischemia (thrombosis/embolism)
192. Most common complication with IVC filters : DVT.
193. Most common component of mixed germ cell tumors : Embryonal Cell Carcinoma
194. Most common congenital abnormality of GI tract : Meckel’s diverticulum
195. Most common congenital anomaly of CNS in live births : Myelomeningocele
196. Most common congenital defect of CNS : Anencephaly.
197. Most common congenital head and neck cyst in a child : Thornwaldt cyst
198. Most common congenital heart disease : Bicuspid aortic valve.
199. Most common congenital intracranial tumor : Epidermoid or inclusion cyst
200. Most common congenital lesion of bile ducts : Choledochal Cyst
201. Most common congenital skeletal dysplasia : Achondroplasia.
202. Most common congenital solid tumor in the newborn : Sacrococcygeal Teratoma (1:40K live births)
203. Most common cranial nerve affected by a pituitary macroadenoma : CN VI.
204. Most common cranial nerve to be affected with schwannoma : VIII
205. Most common craniofacial malformation : Facial Clefting
206. Most common crystalline arthropathy : CPPD
207. Most common CT finding in bowel ischemia : Bowel wall thickening.
208. Most common cyanotic congenital heart malformation beyond neonatal period : TOF
209. Most common cyst of the jaw : Radicular cyst = Periapical cyst
210. Most common cystic lesion of prostate : Cystic degeneration of BPH
211. Most common cystic tumor of pancreas : Mucinous cystic neoplasm
212. Most common diffuse breast disorder : Fibrocystic disease of breast.
213. Most common diffuse gray matter degenerative disease : Alzheimer’s
214. Most common dislocated auditory ossicle longitudinal temporal bone fracture : Incus
215. Most common dislocation in adult : Glenohumeral.
216. Most common dislocation in child : Elbow.
217. Most common epididymal neoplasm : Adenomatoid tumor
218. Most common estrogenic ovarian tumor : Granulosa Cell Tumor
219. Most common etiology for chronic temporal lobe epilepsy : Ganglioglioma
220. Most common etiology for multiple small gastric polyps : Hyperplastic polyps.
221. Most common etiology for osteomyelitis : Staphylococcus aureus.
222. Most common etiology of bilaterally enlarged, hyperechoic kidneys in newborn infant : ARPKD.
223. Most common etiology of mesenteric adenitis : Viral
224. Most common etiology of pneumomediastinum : Alveolar rupture.
225. Most common etiology of rickets : Vitamin D deficiency.
226. Most common extra-adrenal site of pheochromocytoma : Organ of Zuckerkandl.
227. Most common extraaxial neoplasm of CNS : Meningioma
228. Most common extragonadal site of primary germ cell tumors : Anterior mediastinum.
229. Most common extrapulmonary site of tuberculosis : Urinary tract
230. Most common fetal cardiac anomaly seen on 4 chamber view US : AV canal defect (aka ECD)
231. Most common fibromatosis in childhood : Infantile Myofibromatosis
232. Most common finding of a tubal pregnancy seen on US images Adnexal mass separate from ovary
233. Most common finding of contralateral kidney in MCKD : Reflux
234. Most common fluid collection seen in transplant patients : Lymphoceles.
235. Most common form of aortic stenosis : Valvular
236. Most common form of carpal instability : DISI
237. Most common form of emphysema in alpha-1 antitrypsin deficiency : Panlobular emphysema
238. Most common form of emphysema in nonsmokers : Panlobular emphysema
239. Most common form of emphysema in smokers : Centrilobular emphysema
240. Most common form of hypertrophic cardiomyopathy : Asymmetric involvement of the interventricular septum
241. Most common form of skeletal dysplasia : Acquired skeletal dysplasia.
242. Most common form of systemic vasculitis in adults : Giant cell (temporal) arteritis
243. Most common fracture of forearm : Colles
244. Most common functional tumors of the ovary : Sex cord–stromal tumors
245. Most common fungal infection in AIDS : Cryptococcus.
246. Most common genitourinary organ affected by neurofibromas : Urinary bladder
247. Most common germ cell tumor associated with excessive hCG production :Choriocarcinoma.
248. Most common germ cell tumor associated with excessive hCG production after choriocarcinoma : Dysgerminoma.
249. Most common GI neoplasm : Adenoma
250. Most common GI tract location for primary extranodal lymphoma : Stomach, usually NHL type.
251. Most common glial tumor in adults : Ependymoma
252. Most common glial tumor in NF 1 : JPA.
253. Most common glial tumor with microcalcifications : Oligodendroglioma
254. Most common gynecologic neoplasm : Uterine Leiomyoma
255. Most common hereditary hypercoagulable condition : Factor V Leiden
256. Most common hereditary leukodystrophy : Metachromatic leukodystrophy
257. Most common histologic type of bronchogenic carcinoma associated with cavitation : Squamous
258. Most common histologic type of bronchogenic carcinoma associated with pancoast tumor : Squamous
259. Most common histologic type of bronchogenic carcinoma associated with pleural effusion : Adenocarcinoma
260. Most common histologic type of lung cancer associated with asbestosis exposure : BAC
261. Most common histologic type of primary cutaneous lymphoma :T-cell lymphoma
262. Most common ILD to be found in association with collagen vascular disease : NSIP
263. Most common indication for percutaneous vertebroplasty : Osteoporosis.
264. Most common infection to cause cerebellar hypoplasia & migration anomalies : CMV
265. Most common infratentorial neoplasm in an adult : Metastases
266. Most common inherited disease among Caucasian Americans : CF
267. Most common internal enhancement pattern in DCIS with non mass like enhancement : Clumped enhancement
268. Most common intracranial for site of teratomas : Pineal region.
269. Most common intracranial presentation of TB : Tuberculous meningitis.
270. Most common intramedullary spinal neoplasm in adults : Ependymoma of Spinal Cord
271. Most common intramedullary tumor in children : Astrocytoma
272. Most common intramedullary tumor of adults : Ependymoma.
273. Most common intraocular neoplasm in childhood : Retinoblastoma
274. Most common intraorbital tumors found in adults : Cavernous hemangiomas.
275. Most common intrathoracic fetal anomaly : Congenital diaphragmatic Hernia
276. Most common intrathoracic foregut cyst : Bronchogenic Cyst
277. Most common intrauterine CNS infection : CMV
278. Most common intravascular venous tumor : Leiomyosarcoma of IVC
279. Most common in-utero renal tumor : Mesoblastic nephroma.
280. Most common invasive gynecologic malignancy : Endometrial malignancy
281. Most common islet cell tumor in MEN 1 : Gastrinoma
282. Most common islet cell tumor of the pancreas : Insulinoma.
283. Most common joint involved in synovial osteochondromatosis : Knee
284. Most common lesion to cause expansion of paranasal sinus : Mucocele
285. Most common lethal bone dysplasia : Osteogenesis imperfecta type II ?
286. Most common liver tumor after metastases : Hemangioma
287. Most common lobe affected in bronchial atresia : Left upper lobe.
288. Most common location for a cephalhematoma : Parietal
289. Most common location for a gastric diverticulum : Posterior wall of the gastric fundus.
290. Most common location for a pilocytic astrocytoma : Cerebellum
291. Most common location for a solitary myeloma of the bone : Thoracolumbar spine
292. Most common location for a synovial sarcoma : Knee
293. Most common location for a Tarlov cyst : Posterior rootlets of S2 + S3
294. Most common location for abdominal sarcoid involvement : Stomach
295. Most common location for atelectatic asbestos pseudotumor : Posteromedial & -lateral basal region of lower lobes
296. Most common location for chordomas : Sacral spine.
297. Most common location for gallbladder perforation : Fundus
298. Most common location for Sclerosing Osteomyelitis of Garré (sterile Osteomyelitis) : Mandible
299. Most common location for typhlitis : Cecum.
300. Most common location for well-differentiated liposarcoma : Thigh
301. Most common location in biliary tree for cholangiocarcinoma : Upper third/perihilar region.
302. Most common location in the spine for an osteochondroma : Cervical (C2) followed by thoracic T8
303. Most common location of a meningioma in the spine : Thoracic spinal cord
304. Most common location of a periurethral diverticulum in a female : Posterolateral.
305. Most common location of an ectopic pregnancy : Ampullary region of the fallopian tube.
306. Most common location of benign and malignant masses in breast : Upper outer quadrant
307. Most common location of bronchogenic carcinoma : Right upper lobe
308. Most common location of coarctation : Postductal beyond the origin of the left subclavian artery.
309. Most common location of coronary calcifications : LAD.
310. Most common location of DAI : Frontotemporal gray–white matter junction.
311. Most common location of GIST : Stomach.
312. Most common location of GU obstruction in a neonatal male : Ureteropelvic junction.
313. Most common location of intracranial dissection : Vertebral arteries.
314. Most common location of intraorbital abscess : Subperiosteal space on medial wall.
315. Most common location of intraventricular meningioma : Atrium of the lateral ventricle.
316. Most common location of oligodendroglioma : Frontal lobe.
317. Most common location of pleomorphic xanthoastrocytoma : Temporal lobes.
318. Most common location of pulmonary sequestration : Posterior medial lower.
319. Most common location of PVNS : Knee.
320. Most common location of sarcoidosis in spinal cord : Cervical.
321. Most common location of the biliary embryonal Rhabdomyosarcoma : CBD
322. Most common location of triquetral fracture is dorsal avulsion
323. Most common location to find a lithopedion : Adnexae
324. Most common location to see intravertebral vacuum phenomenon (Kümmell Disease) : Thoracolumbar junction
325. Most common lung infection in HIV: Bacterial pneumonia
326. Most common lung mass : Granuloma
327. Most common lysosomal storage disorder : Gaucher’s disease
328. Most common malformation associated with callosal agenesis : Dandy-Walker malformation.
329. Most common malignancy of childhood : Leukemia.
330. Most common malignancy of parotid gland in adult : Mucoepidermoid carcinoma.
331. Most common malignant abdominal neoplasm in children 1–8 years old : Wilms Tumor.
332. Most common malignant bone tumor in children : Ewings
333. Most common malignant cause of bilateral global renal enlargement : Lymphoma.
334. Most common malignant neoplasm of diaphragm : Fibrosarcoma.
335. Most common malignant neoplasm of the spleen : Lymphoma.
336. Most common malignant ovarian neoplasm : Serous adenocarcinoma.
337. Most common malignant ovarian neoplasm : Serous cystadenocarcinoma.
338. Most common malignant primary bone tumor in young adults + children : Osteosarcoma
339. Most common malignant radiation-induced tumor of the musculoskeletal system : MFH
340. Most common malignant sex cord–stromal tumor : Granulosa cell tumor
341. Most common malignant testicular neoplasm : Nonseminomatous germ cell tumors
342. Most common malignant tumor affecting ribs of children + adolescents : Ewings Sarcoma
343. Most common malignant tumor of the abdomen in patients with NF1 Malignant peripheral nerve sheath tumor
344. Most common malignant tumor of the duodenum : Adenocarcinoma.
345. Most common malignant tumor of the heart : Angiosarcoma
346. Most common malignant tumor of the small bowel : Carcinoid
347. Most common mammographic finding in DCIS : Microcalcifications
348. Most common mammographic finding in Infiltrating/Invasive Lobular Carcinoma : Architectural distortion.
349. Most common manifestation of asbestosis exposure : Pleural plaques
350. Most common manifestation of asbestos-related pleural disease : Pleural effusion
351. Most common manifestation of blunt chest trauma : Pulmonary contusion
352. Most common mass lesion of the cerebellopontine angle after acoustic schwannoma : Meningioma
353. Most common mediastinal germ cell tumor : Seminoma.
354. Most common mediastinal mass in a child between the ages of 6 & 12 years old : Lymphoma
355. Most common mediastinal neurogenic tumor : Schwannoma
356. Most common mesenchymal origin neoplasm of GI tract : GIST
357. Most common metabolic liver disease in children : Hepatic cirrhosis in homozygous alpha-1 Antitrypsin Deficiency
358. Most common metastases to the spleen : Breast carcinoma
359. Most common metastasis to the heart : Melanoma
360. Most common metastatic cause of linitis plastica : Breast carcinoma
361. Most common metatarsal to have a stress fracture : Second metatarsal.
362. Most common missed type of breast cancer on mammography : Infiltrating/Invasive Lobular Carcinoma.
363. Most common mitral valve abnormality in the Western world : Non-rheumatic mitral valve disease.
364. Most common monodermal teratoma : Struma ovarii.
365. Most common motor neuron disease : ALS.
366. Most common MR imaging finding in DCIS : Non-masslike enhancement.
367. Most common mycotic pneumonia in an AIDS patient : Cryptococcus.
368. Most common natural outcome of the VSD : Spontaneous complete closure.
369. Most common neonatal cyanotic congenital heart malformation : TGV
370. Most common neonatal lesion of adrenal gland : Nontraumatic Adrenal Hemorrhage.
371. Most common neoplasm of conus medullaris : Myxopapillary Ependymoma of Spinal Cord.
372. Most common neoplasm of internal auditory canal / cerebellopontine angle : Vestibular Schwannoma.
373. Most common neoplasm of the gastrointestinal tract in patients with NF1: Neurofibromas.
374. Most common nerve to be involved in tarsal tunnel syndrome : Posterior tibial nerve.
375. Most common nonepidemic meningoencephalitis in immunocompetent individuals in US : Herpes Encephalitis.
376. Most common nonepithelial malignant bladder tumor : Leiomyosarcoma.
377. Most common nonepithelial tumor in the colon : Lipoma.
378. Most common nonepithelial tumor of the bladder : Leiomyoma.
379. Most common nonglial primary tumors of the central nervous system : Meningiomas.
380. Most common nonlymphoproliferative primary malignant tumor of the spine in adults : Chordoma.
381. Most common nonlymphoproliferative primary malignant tumor of the spine in children : PNET.
382. Most common nontraumatic cause of acute limp in a child : Toxic synovitis.
383. Most common non-traumatic cause of facial nerve paralysis & hearing loss : CPA tumor.
384. Most common odontogenic mass : Odontoma= odontogenic hamartomatous malformation.
385. Most common of all alimentary tract duplications : Small Bowel Duplication Cyst.
386. Most common of cerebral vascular malformation : DVA.
387. Most common opportunistic infection in AIDS : Toxoplasmosis.
388. Most common organism involved in pancreatic abscess : E. Coli.
389. Most common organism of acute pyogenic meningitis in infants & children : N. meningitides.
390. Most common origin of cystic artery : Right hepatic artery.
391. Most common osteochondrodysplasia : Hereditary Multiple Exostoses
392. Most common ovarian neoplasm : Dermoid aka dermoid cyst = Mature cystic teratoma
393. Most common ovarian tumor-related morbidity : Bowel obstruction
394. Most common pancreatic abnormality in adult pt's with CF : Complete fatty replacement
395. Most common paraneoplastic disease associated with thymoma : Myasthenia gravis
396. Most common parasitic infection involving CNS in developing countries : Cysticercosis
397. Most common parotid disease in children : Mumps parotitis.
398. Most common pattern of bronchial arteries : Two left & one right bronchial artery
399. Most common pattern of enhancement at DE MR cardiac imaging : Patchy midwall enhancement with multiple foci
400. Most common pattern of hepatic involvement of secondary lymphoma : Diffuse infiltrative
401. Most common pattern of spread in Gallbladder Carcinoma : Direct spread.
402. Most common pediatric glioma : JPA
403. Most common pediatric tumor causing isosexual precocious puberty in a girl : Granulosa cell tumor
404. Most common phakomatoses : NF1
405. Most common pineal tumor : Pineal Germinoma
406. Most common predisposing cause to develop pneumothorax during percutaneous lung biopsy : COPD
407. Most common predisposing disorder of secondary spontaneous pneumothorax : COPD
408. Most common pregnancy-related mortality in the first trimester Ectopic pregnancy
409. Most common presentation for idiopathic pulmonary fibrosis : Dyspnea
410. Most common presentation in stuck twin syndrome : Monochorionic diamniotic
411. Most common presentation of bronchoalveolar cell carcinoma (BAC) : Solitary pulmonary nodule.
412. Most common presentation of GIST on cross sectional imaging : Cystic areas of necrosis.
413. Most common presentation of mesoblastic nephroma : Palpable mass at birth.
414. Most common presentation of neurocysticercosis : Seizures.
415. Most common presenting symptom of Osler Weber Rendu : Hemoptysis.
416. Most common primary benign mesenteric tumor : Desmoid.
417. Most common primary brain tumor : GBM.
418. Most common primary cardiac tumors in adults : Myxomas.
419. Most common primary cerebellar mass in an adult : Hemangioblastoma
420. Most common primary demyelinating disease : MS
421. Most common primary female urethral malignancy : Squamous cell carcinoma

422. Most common primary hepatic neoplasm in infants & children less than 5 years old : Hepatoblastoma
423. Most common primary intraocular neoplasm in adult Caucasian : Uveal Melanoma
424. Most common primary lung tumor under age 16 : Bronchial Adenoma
425. Most common primary malignant rib tumor : Chondrosarcoma
426. Most common primary malignant sacral tumor : Sacrococcygeal Chordoma
427. Most common primary malignant soft-tissue tumor of late adult life : Soft-tissue MFH
428. Most common primary neoplasm of the spleen : Cavernous hemangioma
429. Most common primary neoplasms of the anterior superior mediastinum Thymomas.
430. Most common primary posterior mediastinal neoplasms :Neurogenic tumors
431. Most common primary tumor of the diaphragm : Lipoma
432. Most common radiation-induced CNS tumor : Meningioma
433. Most common reason for cardiac transplantation : Dilated cardiomyopathy
434. Most common recognized CNS manifestation of VHL disease : Hemangioblastoma of CNS
435. Most common relevant finding on cavogram for IVC filter placement : Circumaortic left renal vein.
436. Most common renal fusion anomaly : Horseshoe kidney
437. Most common renal mass in a 3 months old infant : Mesoblastic nephroma
438. Most common respiratory cause of cold agglutinin production : Mycoplasma pneumonia
439. Most common retinal infection in AIDS : Toxoplasmosis
440. Most common right cardiophrenic angle mass : Epicardial fat-pad/lipoma
441. Most common segment involved in tracheobronchial injury : Right lower lobe bronchus.
442. Most common sex cord-stromal cell tumor : Ovarian Fibroma
443. Most common sign of failing dialysis graft : Increased venous pressures
444. Most common sign of tuberous sclerosis : Myoclonic seizures
445. Most common single cause of breast lumps in females between 35 to 55 years of age : Breast cyst
446. Most common site for an intracardiac papillary fibroelastoma : Aortic valve.
447. Most common site for aneurysm in the chest : Descending thoracic aorta.
448. Most common site for cardiac myxoma : Left atrium
449. Most common site for intra cardiac thrombus formation : Atrial appendage.
450. Most common site for optic melanoma metastases : Liver.
451. Most common site for penetrating aortic ulcers : Descending thoracic aorta
452. Most common site of abdominal involvement in Hodgkins disease : Spleen
453. Most common site of aortic dissection : Prox. Desc. Thoracic aorta near ductus lig. attachment
454. Most common site of biliary tract injury caused by blunt abdominal trauma : Gallbladder
455. Most common site of monostotic fibrous dysplasia : Ribs
456. Most common site of rupture of sinus of Valsalva aneurysm : RV followed by RA.
457. Most common solid extracranial tumor of childhood : Neuroblastoma
458. Most common spermatic cord tumor : Lipoma
459. Most common spinal cord segment of lymphoma of spinal cord : Cervical
460. Most common spinal cord tumor : Ependymoma
461. Most common spinal location for cord astrocytoma : Thoracic
462. Most common spinal location for cord ependymoma : Cervical
463. Most common subcortical degenerative disease : Parkinson’s
464. Most common subglottic soft-tissue upper resp. tract obstructing mass in neonates : Subglottic Hemangioma
465. Most common submucosal tumor in colon : Lipoma
466. Most common subtype of NHL involving the esophagus : Diffuse large B-cell lymphoma
467. Most common subtype of renal cell carcinoma : Clear cell adenocarcinomas
468. Most common suprasellar mass : Craniopharyngioma
469. Most common syndromic islet cell tumor : Insulinoma
470. Most common systemic allergic hypersensitivity-related acute small-vessel vasculitis in children : HSP
471. Most common systemic fungal infection in immunocompromised patients : Candidiasis Of Liver
472. Most common tarsal bone to get fractured : Calcaneus
473. Most common tarsal coalition : Talocalcaneal
474. Most common testicular tumor in a young boy : Yolk sac tumor
475. Most common tibial plateau fractures : Lateral tibial plateau (Schatzker classification type I–III)
476. Most common trigonal intraventricular mass in adulthood : Meningioma
477. Most common tumor of adenohypophysis : Pituitary Adenoma
478. Most common tumor of genitourinary tract : Metachronous TCC
479. Most common tumor of the appendix : Carcinoid
480. Most common tumor of the esophagus : Leiomyomas
481. Most common tumor of the minor salivary glands : Adenoid Cystic Carcinoma
482. Most common type of abdominal wall hernia : Inguinal hernia
483. Most common type of ASD : Ostium secundum
484. Most common type of brain hernaition : anterior / uncal transtentorial
485. Most common type of brain herniation : Subfalcine herniation
486. Most common type of C2 fractures : Type 2
487. Most common type of cancer to arise from a thyroglossal duct cyst : Papillary carcinoma
488. Most common type of cardiomyopathy : Dilated cardiomyopathy
489. Most common type of choledochal cyst : fusiform dilatation of the extrahepatic duct Type 1c
490. Most common type of congenital internal hernia : Left paraduodenal hernia
491. Most common type of encephalocele in SE Asia: Sincipital Encephalocele
492. Most common type of encephalocele in US : Occipital Encephalocele
493. Most common type of endoleak in the abdominal aorta : Type II endoleak
494. Most common type of endoleak in the thoracic aorta : Type I endoleak
495. Most common type of fracture of the proximal 5th metatarsal bone : Peroneus brevis avulsion fracture.
496. Most common type of gallbladder inflammation : Chronic cholecystitis
497. Most common type of internal hernia : Postoperative, transmesenteric hernias.
498. Most common type of intrapulmonary involvement of Hodgkins disease : Bronchovascular form.
499. Most common type of liver abscess : Pyogenic Liver Abscess
500. Most common type of lymphoma involving the head and neck region : Diffuse large B-cell lymphoma
501. Most common type of malignancy in undescended testis : Seminoma
502. Most common type of meniscal tear : OBLIQUE / FLAP TEAR
503. Most common type of Mucopolysaccharidoses : Morquio (Type IV)
504. Most common type of non-iatrogenic internal hernia : Left paraduodenal hernia
505. Most common type of noninflammatory odontogenic cyst : Dentigerous cyst = follicular cyst
506. Most common type of of pituitary adenomas : Prolactinoma
507. Most common type of pulmonary amyloidosis : Tracheobronchial type
508. Most common type of pulmonary NHL involvement Secondary involvement due to direct hilar extension
509. Most common type of sarcoma of the larynx : Chondrosarcoma.
510. Most common type of sarcoma of the liver : Angiosarcoma
511. Most common type of temporal bone fractures : Longitudinal type
512. Most common type of total anomalous pulmonary venous connection : Supracardiac, type 1
513. Most common type of VSD : Membranous
514. Most common US characteristic of an ovarian germ cell tumor : Marked hyperechogenic focus
515. Most common vascular tumor of orbit in children : Capillary Hemangioma of Orbit
516. Most common ventral hernia : Umbilical hernia
517. Most common virilizing tumor of ovary : Sertoli-Leydig Cell Tumor
518. Most commonly affected cranial nerve in Lyme disease : Facial nerve
519. Most commonly entrapped fragment in a child after reduction of elbow disloc. : Medial epicondyle.
520. Most commonly entrapped fragment in adult after reduction of elbow dislocation : Coronoid process.
521. Most commonly injured ankle ligament :Anterior talofibular
522. Most commonly involved joint with Charcot arthropathy : Tarsal & tarsometatarsal.
523. Most commonly involved segment of the colon with diverticulitis in USA : Sigmoid colon
524. Most common type of shoulder dislocation : Anterior.
525. Most common type of hip dislocation : Posterior
526. Most common type of odontogenic tumor : Ameloblastoma.
527. Most common type of benign mandibular tumor : Ameloblastoma