Germ Cell Tumours/ASPHO

Question 1

age distribution in GCTs?

Answer 1

bimodal; peak <3 years and at adolescence

Question 2

what types of GCTs seen in younger age mostly?

Answer 2

<3 years: extra gonadal, testicular

Question 3

what types of GCTs seen in adolescents?

Answer 3

gonadal

Question 4

2 main types of peds GCTs?

Answer 4

seminatous (germinomatous) adn non-seminatous

Question 5

what 3 tumours make up category of seminomatous GCTs?

Answer 5

seminoma (testes), dysgerminoma (ovary), germinoma (extra-gonadal)

Question 6

what 4 tumours make up non-seminatous category?

Answer 6

embryonal ca, yolk sac tumour, choriocarcinoma, teratoma

Question 7

embryonal ca: ___ cells that histologically resemble ___ cells from the ___

Answer 7

undifferentiated; embryonic; blastocyst

Question 8

yolk sac tumours: __ ___ malig GCT in ___ children; component of ___ and ___ ___

Answer 8

most common; young; embryonic; extraembryonic endoderm

Question 9

choriocarcinoma: very ___, represents ____ ___

Answer 9

rare; trophoblastic differentiation

Question 10

teratoma: ____ ___ of ____ cell types from ___ ___ ___ cell layers; if a component acquires ___ ___: ____ teratoma

Answer 10

disordered mixture; differentiated; all 3 somatic; neuronal differentiation; immature teratoma

Question 11

classify GCTs how?

Answer 11

Type 1 or Type 2

Question 12

describe type 1 GCTs

Answer 12

children <4 yrs; usually present as teratoma, YST, or mixtures of the types

Question 13

describe type 2 GCTs

Answer 13

puberty- young adulthood; full range of germinamatous and non-germinamatous histologies; often associated with a presumptive precursor lesion known as germ cell neoplasia in situ (GNCIS, usually seen in normal tissue adjacent to tumour)

Question 14

germ cell tumours arise from what?

Answer 14

primoridal cells involved in gametogenesis at diff stages of development (type 1 vs type 2)…aberrant caudad or cephalad migration of germ cells–> midline extragonadal tumours

Question 15

describe the molecular genetics in type 1 vs type 2 GCTs

Answer 15

type 1: gain of 1q, 11q, 20q, 22…loss of 1p, 6q, 16q…partial loss of genomic imprinting….type 2: amplification of chrom 12, amplification of X chromosome and loss of genomic imprinting

Question 16

risk factors for pediatric GCTs?

Answer 16

"SK-GCT"
Klinefelter
Swyer syndrome 46XY
turner syndrome 47XO
crypto-orchidism
GU anomalies (hernia, hydrocele)

Question 17

how do GCTs present?

Answer 17

• ovarian: abdo pain/mass
• precocious puberty
• amenorrhea, virilziation
• testicular non-tender mass
• constipation, urinary retention if sacrococcygeal site
• chest pain, resp distress if mediastinal

Question 18

how does ovarian sex cord stromal tumor present?

Answer 18

precocious puberty (granulosa cell tumour, young kids)
amenorrhea and/or virilizatio (sertoli-leydig tumour, adolescents)

Question 19

test to dx GCT?

Answer 19

CT/MRI of primary adn met work up with bone scan, chest ct

Question 20

how do girls with gonadal tumours present?

Answer 20

ovarian tumours after age 3

Question 21

how do boys with gonadal tumours present?

Answer 21

testicular tumours before age 4 or after age 13

Question 22

extragonadal tumours tend to be ___ tumours presenting before age ___ or ___ tumours presenting AFTER age ___

Answer 22

sacro-coccyxygeal; 4; mediastinal; 9

Question 23

GCTs: what % are gonadal vs. extragonadal?

Answer 23

gonadal: 41%
extra: 59%

Question 24

age cut off for gonadal vs extragonadal disribution?

Answer 24

UNDER age 15, tend to be extragonadal…15 and OVER tend to be gonadal

Question 25

what % of peds GCTs are stage 3 or 4?

Answer 25

80%!