Pediatric Pathology

Question 1

What is placentomegaly and what are it’s two main associations?

Answer 1

>600 g (Fetal:Placental weight ration less than 3:1)–THINK MATERNAL DIABETES AND BECKWITH-WEIDEMANN SYNDROME Most often due to villous edema; also severe maternal anemia, fetal anemia, fetal hydrops, congenital syphilis/TORCH

Question 2

What is the characteristic placental lesion associated with oligohydramnios?

Answer 2

Amnion nodosum – granular, pick off, associated with chronically decreased amnionic fluid (renal agenesis, premature or prolonged amniorrhea, donor of twintwin transfusion or other congenital anomaly)

Question 3

What organisms cause placental intervillous abscesses and septic infarcts?

Answer 3

Listeria monocytogenes and Campylobacter fetus

Question 4

What organism causes yellow, punctate microabscesses on surface of umbilical cord;?

Answer 4

Candida (“peripheral funisitis”)

Question 5

What organism causes a characteristic light green color to the placenta?

Answer 5

Fusobacterium

Question 6

What two organisms are known to cause necrotizing funisitis?

Answer 6

Syphilis and HSV

Question 7

If you see placental diffuse lymphohistiocytic inflammation, “diffuse sclerosing villitis”, what organisms should you think of?

Answer 7

TORCH (lymphoplasmacytic inflammation associated with syphilis, CMV, HSV, Rubella; plasma cells associated with CMV)

Question 8

What organism causes chronic (histiocytic) intervillositis?

Answer 8

Malaria (has malarial pigment!–blue black granular pigment)

Question 9

What is the formula for calculating Kleihauer-Betke acid elution technique to quantify volume of fetomaternal hemorrhage by staining for cells containing fetal hemoglobin in the maternal circulation?

Answer 9

percentage of fetal blood loss = (3200 x fetal cell count)/(fetal weight kg x maternal cell count)

Question 10

What placental lesion is can be associated with HELLP syndrome and is characterized by recurrent reproductive failure, severe normotensive intrauterine growth retardation; anomalous procoagulant expression on trophoblast, inappropriate secretion of fibrinoid?

Answer 10

Massive Perivillous Fibrinoid (Maternal Floor Infarction)

Question 11

What is the definition of chorangiosis?

Answer 11

>10 capillary vessels in 10 tertiary villi under 10x in multiple fields Associated with associated with maternal diabetes, placentomegaly, delayed villous maturation, and chronic villitis

Question 12

What are the placental associations with fetal neurological impairment?

Answer 12

Severe chorioamnionitis, Extensive avascular villi, Diffuse chorioamnionic hemosiderosis

Question 13

What are the fetal anomalies associated with a single umbilical artery?

Answer 13

~20% have associated fetal anomalies: cardiovascular, GI, esophageal atresia, renal defects, multiple anomaly syndromes, TRISOMY 18

Question 14

What are the microscopic characteristics of a partial mole?

Answer 14

DIMORPHIC population of large and small villi without intermediate forms, irregular villous contours often with MULTICELLULAR TROPHOBLAST INCLUSIONS within villous stroma

Question 15

What are the physical characteristics of Trisomy 13 (Patau Syndrome)?

Answer 15

Cleft lip/palate, polydactyly, scalp defects, micropthalmia, sloping forehead, hypertelorism and proboscis (long nose)

Question 16

What are the physical characteristics of Trisomy 18 (Edwards Syndrome)

Answer 16

Prominent occiput, micrognathia, rocker bottom feet, short sternum, narrow pelvis, clenched fists with overlapping second and 5th fingers, short dorsiflexed first toe, partial syndactyly of toes, upturned nares

Question 17

What disease is associated with orange sand uric acid crystals found in diaper?

Answer 17

Lesch Nyhan Syndrome (X linked, affects males)

Question 18

What gene is associated with Hirschsprung’s?

Answer 18

RET

Question 19

Which two pediatric tumors have a t(12;15) translocation?

Answer 19

Congenital mesoblastic nephroma and fibrosarcoma

Question 20

Which 3 pediatric tumors share t(11;22) translocation?

Answer 20

Ewings, PNET and Desmoplastic Small Round Cell Tumor (but has a different breakpoint than Ewing’s and PNET)

Question 21

What syndrome can hepatoblastoma be associated with?

Answer 21

FAP (Familial Adenomatous Polyposis)

Question 22

What does the VATER syndrome stand for?

Answer 22

vertebral or vascular, anal, tracheo-esophageal, renal or radial anomalies

Question 23

What are the good prognostic indicators in pre B-ALL?

Answer 23

Hyperdiploidy 51-65 (DI 1.16 – 1.6) t(12;21)(p12;q22) TEL-AML1

Question 24

What are the bad prognostic indicators in pre B-ALL?

Answer 24

t(9;22) BCR-ABL

t(4;11) MLL-AF4

t(1;19) E2A-PBX Hypodiploidy

Question 25

BQ! What disease is this EM showing?

Answer 25

Fabry’s Disease: X-linked lysosomal storage disease that is caused by deficient activity of lysosomal enzyme α -galactosidase A. Abnormal storage product, “zebra
bodies” are seen in a podocyte.

Question 26

What heart abnormality is seen in Turner’s?

Answer 26

Preductal coarctation of the aorta

They also get single umbilical artery

Question 27

What are the 4 components of Tetralogy of Fallot?

Answer 27

Right to left shunt

– Overriding aorta

– Pulmonary valve stenosis

– Ventricular septal defect

– Right ventricular hypertrophy

Question 28

What is the syndrome associated with WT1? WT2?

Answer 28

WAGR syndrome (WT-1)

– Wilms tumor

– Aniridia

– Genital anomalies

– Mental Retardation

Beckwith-Wiedemann syndrome (WT-2)

• Wilms tumor
• Hepatoblastoma
• Congenital anomalies

– Macroglossia

– Macrosomia

– Midline abdominal wall defects

• Ear abnormalities
• Neonatal hypoglycemia

Question 29

What is the MOST IMPORTANT factor in prognosis of neuroblastoma that trumps everything else?

Answer 29

Age of the patient (THE most impt)

<1yr do ok

>5 poor

Good prognosis: hyperdiplioid, no structual chr abnormalities and expression of TrkA neurotrophin receptor

Question 30

What is the gene mutation associated with transient leukemia/transient myeloproliferative disorder in Down’s syndrome?

Answer 30

GATA1 gene mutation

Question 31

This tumor from the finger of a young child has a VERY characteristic appearance of these spindle cells with eosinophilic hyaline globules. What is the tumor?

Answer 31

Infantile fibromatosis

Question 32

This pediatric liver tumor shows poorly differentiated spindle cells. What is the tumor and what is its unique staining pattern?

Answer 32

Undifferentiated Embryonal sarcoma (UES)

IHC:

 Desmin +

 MSA +

 Actin +

 CK +

 Myoglobin -

 Vimentin, alpha-1-antitrypsin and alpha-1- antichymotrypsin +

Question 33

What pediatric soft tissue tumor has characteristic dot like staining with desmin?

Answer 33

Desmoplastic small round blue cell tumor

Question 34

What are some poor prognostic factors in neuroblastoma?

Answer 34

MYC-N amplification (>10 copies/cell)

ALK amplification

Chromosome 1p36.3 or 11q23 deletion and gain of 17q

*although not formally used in risk stratification, chr 11q loss, unlike 1p loss, is seen in ABSENCE of NMYC amplification and may be independent marker of prognosis in NMYC non amplified diploid cases

Near-diploid DNA content (patients <18 months with metastatic disease)

Increasing age

*tend to express TrkB neurotrophin and BDNF

Question 35

What is the most common solid tumor in childhood?

Answer 35

Rhabdomyosarcoma

*less than 1 year old is neuroblastoma

Question 36

What hereditary disease causes cholesterol accumulation in fixed tissue macrophages, shows this “zebra body storage” on EM and usually die before 3yo with cerebral atrophy?

Answer 36

Niemann Pick

Sphingomyelinase deficiency (sphingomyelin accumulates in macrophages and neurons)

Question 37

What is the most common congenital cardiac malformation? Most common congenital cardiac anomaly?

Answer 37

• “VSD is most common congenital cardiac malformation”
• “ASD is most common congenital cardiac anomaly, usually asymptomatic until adulthood”