Pediatric Tumors Pathology

Question 1

Nephroblastoma (wilms tumor) immunohistochemistery

Answer 1

WT1 in blastemal and epithelial components

Question 2

Microscopy of wilms tumor (nephroblastoma)

Answer 2

1. Blastema
2. Epithelial component
3. Stroma

Question 3

Nephroblastoma genetic presentations

Answer 3

Syndromic:
WAGR: WT1 
Denys Drash: WT1
Beckwith wiedeman: WT2 
Bloom:DNA repair defect

Sporadic
Beta catenin encoding gene (gain of function)
Micro DNA processing proteins mutations
P53 mutation: poor prognosis

Question 4

Staging of nephroblastoma(wilms tumor)

Answer 4

I. Limited to the kidney
II. Beyond kidney but completely resected
III. Tumour in abdomen
IV. Haematogenous metastases
V. Bilateral renal tumours

Question 5

What is the most common abdominal. Tumor in children

Answer 5

Neuroblastoma

Question 6

What doea anaplastic lymphoma kinase(ALK) +ve mean in a neuroblastoma?

Answer 6

Very poor prognosis

Question 7

Immunohistochemistery for classic neuroblastoma

Answer 7

neuron- specific enolase

Question 8

What is the indicator of poor prognosis in classic neuroblastoma?

Answer 8

MK index (mitosis and karyorrhectic cells)

Question 9

Which oncogene is amplified in poor prognostic neuroblastoma?

Answer 9

MYCN oncogene on Ch2 distal arm

Question 10

What is the origin of neuroblastoma

Answer 10

Neural crest cells and sympathetic ganglia

Question 11

Microscopic pic of classic neuroblastoma

Answer 11

Solid sheets of small, primitive-appearing cells
Neuropil
Pseudo rosette
High MK index

Question 12

What is the sign of maturation in neuroblastoma

Answer 12

Presence of ganglion cells

Question 13

Grading of neuronlastoma

Answer 13

Grade 1: low mitotic count AND calcification
Grade 2: low mitotic count OR calcification
Grade 3: Neither feature present, i.e. high mitotic
count, no calcification

Question 14

Staging of neuroblastoma

Answer 14

I. Confined to organ of origin
II. Beyond I but not crossing midline
III. Tumour crosses midline
IV. As III + distant metastases
IV-S. Fulfil criteria for I or II but with metastases in liver, skin and/or bone marrow

Question 15

Blueberry muffin baby denotes which type of tumors

Answer 15

Neuroblastoma in neonates

Question 16

What doea periorbital metastases of neuroblastoma show in cl/p?

Answer 16

Raccoon eyes

Question 17

Which hormones does neuroblastoma produce?

Answer 17

Cathecholamines
High in blood and in urine
VMA AND HVA (Homovanilic acid)

Question 18

What is the gene mutation in retinoblastoma?

Answer 18

Rb gene (13q14)

Question 19

What are the most common sites of metastases in neuroblastoma

Answer 19

Liver, skin, bone marrow

Question 20

What are the sites of metastases in retinoblastoma?

Answer 20

CNS
• Skull
• Distal bones
• Lymph nodes

Question 21

Immunohistochemistery of retinoblastoma

Answer 21

Neuron Specific Enolase [NES] and S100

Question 22

What causes poor prognosis in retinoblastoma

Answer 22

Retrolaminar optic nerve invasion
o Deep choroidal invasion
o Invasion of anterior chamber angle

Question 23

Management of retinoblastoma

Answer 23

Chemo
Radio
Enucliation

Question 24

What is the origin of PNET/ ewing sarcoma?

Answer 24

undifferentiated
mesenchymal cells within the
medullary cavity of neuroectodermal differentiation

Question 25

Onion skin appearance on xray denotes…

Answer 25

Ewing sarcoma

Question 26

Immunohistochemistery of ewing sarcoma

Answer 26

CD99 (MIC 2) stains the cell membrane

Question 27

IHC of embryonal Rhabdomyosarcoma (Rhabdomyoblast)

Answer 27

Desmin +ve

Question 28

IHC of Rhabdomyosarcoma

Answer 28

Desmin, myoglobin, and

muscle specific actin

Question 29

Most common neoplasms of infancy

Answer 29

Heamangiomas

Question 30

Genetic mutation in alveolar Rhabdomyosarcoma

Answer 30

fusions of the FOXO1 gene to either the PAX3 or
the PAX7 gene
Balanced reciprocal translocation
t(2;13)(q35;q14)