Overview

Question 1

What are the 2 broad categories of germ cell tumors?

Answer 1

Gonadal and extragonadal

Question 2

Pineal tumors represent what % of adult and children’s tumors?

Answer 2

Pediatric: 5%

Adult: 1%

Question 3

Germ cell tumors represent what % of pediatric and adult brain tumors?

Answer 3

Pediatric: 0.5%–3% (more frequent in Japan and other Asian countries—up to 11%)

Adult: 1%

Question 4

How would a “germinoma” of the testicles or ovaries be described?

Answer 4

Germinoma is referred to as seminoma in the testicles and dysgerminoma in the ovaries.

Question 5

What are the most common sites of extragonadal germ cell tumors in adults? In children?

Answer 5

In adults: ant mediastinum, retroperitoneum, pineal/suprasellar regions

In children: sacrococcygeal and intracranial

Question 6

What are the 2 subtypes of intracranial germ cell tumors? Which has a more favorable prognosis? Which is more common?

Answer 6

Germinoma and nongerminomatous germ cell tumor (NGGCT). Germinoma has a more favorable prognosis and requires less intensive therapy. Germinomas are more common (two-thirds of all intracranial germ cell tumors).

Question 7

What are 4 subtypes of intracranial NGGCTs?

Answer 7

Endodermal sinus tumor (yolk sac, elevated AFP), choriocarcinoma (elevated β-HCG), teratoma (immature and mature), embryonal (elevated placental alkaline phosphatase [PLAP]), and mixed (25% of NGGCT).

Question 8

What are the median age at Dx and the sex/race predilection for intracranial germinomas?

Answer 8

10–12 yrs, males > females (2–3:1), Asian > white (4% vs. 1% pediatric CNS tumors in Asia vs. the United States)

Question 9

Where do the majority of intracranial germinomas and NGGCTs arise?

Answer 9

Midline proximal 3rd ventricular structures: two-thirds pineal and one-third suprasellar. Other sites include basal ganglia, thalamus, cerebral hemisphere, and cerebellum. 5%–10% present with both pineal and suprasellar tumors, may be bifocal rather than metastatic, and are usually pure germinomas.

Question 10

What % of germinomas have CSF dissemination at Dx?

Answer 10

10%–15%

Question 11

What is the probability of spinal failure in pts with various types of pineal-based tumors without evidence of spinal seeding at Dx?

Answer 11

Mature and immature teratoma: 0%

Mixed NGGCT: 4%

Other NGGCT: 39% (teratomas with malignant transformation and yolk sac tumors)

Germinoma: 17%

Pineocytoma: 0%

Pineal parenchymal tumor (PPT), pineoblastoma, or PPT of intermediate differentiation: 57%

Pineoblastoma and NGGCT have the highest propensity for CSF dissemination. (Schild SE et al., Cancer 1996)

Question 12

What is the typical presentation of a tumor in the pineal region?

Answer 12

↑ ICP (d/t obstructive hydrocephalus, causing, n/v, papilledema, lethargy, somnolence); Parinaud syndrome (decreased upward gaze, accommodates but abnl light response); endocrinopathies rare but DI sometimes observed.

Question 13

Pressure/mass effect on what anatomic structure causes Parinaud syndrome?

Answer 13

Pressure/mass effect on the sup colliculus causes Parinaud syndrome.

Question 14

How do pts with suprasellar masses present?

Answer 14

Triad of visual difficulties (bitemporal hemianopsia), DI, and precocious or delayed/abnl sexual development. Other aspects of hypothalamic/pituitary dysfunction possible, including GH deficiency, hypothyroidism, and adrenal insufficiency.

Question 15

What are the most common locations of CNS germ cell tumors? What are common signs/symptoms?

Answer 15

CNS germ cell tumors are midline tumors. The most common locations include the pineal gland (most common) and the suprasellar region. Pineal tumors can result in obstructive hydrocephalus/Parinaud syndrome. Suprasellar tumors may result in hypothalamic/pituitary dysfunction, including diabetes insipidus.

Jennings, MT. Intracranial germ-cell tumors: natural history and pathogenesis. J Neurosurg. 1985;63:155.