Germ Cell Tumors

Question 1

A _______ is a tumor composed of an admixture of different tissue types representative of ectoderm, endoderm, and mesoderm.

Answer 1

A teratoma is a tumor composed of an admixture of differ-
ent tissue types representative of ectoderm, endoderm, and
mesoderm. A mature teratoma is composed exclusively of fully
differentiated tissues, sometimes arranged in such a manner
as to resemble normal tissue relationships. Mitoses are absent
or rare. An immature teratoma is composed of incompletely
differentiated tissues resembling those of the fetus. Mitoses
typically are present.

Question 2

In the West, CNS germ cell tumors are relatively rare,
accounting for 3% to 5% of all CNS tumors in the pediatric age
group. They are more common in ____, where they account for
as many as 15% to 18% of all CNS tumors occurring in child-
hood.

Answer 2

Asia

Question 3

CNS germ cell tumors arise from primordial germ cells in structures about the third ventricle, with the region of the _____ being the most common site of origin followed by the suprasellar region

Answer 3

pineal gland

Question 4

Most common site:

(NGGCTs):
germinomas:

Answer 4

(NGGCTs) are the most common tumor type in the pineal area

and germinomas in the suprasellar area.

Question 5

Another characteristic presentation of tumors in pineal region is _______ as a result of dorsal midbrain compression.

Answer 5

Parinaud’s syndrome

Question 6

______ of the spinal axis is an essential part of the workup to exclude leptomeningeal dissemination, which is found at diagnosis in approximately 10% of patients with germinomas and 10% to 15% of patients with NGGCTs.

Answer 6

Gadolinium-enhanced MRI

Question 7

Modest elevation of β-human chorionic gonado-

tropin (β-hCG) (

Answer 7

syncytiotrophoblastic cells

choriocarcinoma

yolk-sac tumor or endodermL sinus tumor

Question 8

For tumors in the pineal region with hydrocephalus, the usual surgical approach is an _______ which allows access to the
lesion for biopsy purposes.

Answer 8

endoscopic third ventriculostomy

Question 9

For patients with unifocal disease
without leptomeningeal spread, radiotherapy alone to limited volumes, that is, _____
results in a high probability of local control and a low (0% to
5%) risk of failure in the spinal axis.

Answer 9

whole brain or whole ventricle

Question 10

because germinoma is a very radiosensitive tumor, a fraction size of ___ Gy can be used, which, in theory, further reduces the risk of injury to normal structures

Answer 10

1.5 gy

Question 11

In NGGCT, multimodality approach that includes both chemotherapy and radiotherapy appears to be associated with the best outcome

Answer 11

True

Question 12

In NGGCT, The current

standard of care therefore consists of ____- based chemo-therapy followed by radiotherapy.

Answer 12

platinum

Question 13

In NGGCT, The usual dose to the whole-ventricle volume or CSI is ____ Gy and to the primary site, ____ Gy

Answer 13

30 to 36

54

Question 14

Germ cell tumors of the CNS constitute a group of rare tumors that are morphologic homologs of germinal neoplasms arising in the gonads and at other extragonadal sites. They include the following entities although in many cases more than one tumor type is present:

Answer 14

•  Germinoma
•  Embryonal carcinoma
•  Yolk-sac tumor (endodermal sinus tumor)
•  Choriocarcinoma
•  Teratoma
–Mature
–Immature
–Teratoma with malignant transformation
•  Mixed germ cell tumor