GERMINATE

Q.All are true regarding intracranial germinoma  except

a. the pineal region is the most frequent site

b. Germinomas are tumors of children or young adults.

c. Suprasellar germinomas are  encapsulated

d. suprasellar germinomas are typically midline, centered at or just behind the pituitary infundibulum

e. the posterior pituitary bright spot is absent in most cases

ANS.---c

Suprasellar germinomas are not encapsulated. They are very infiltrative, adherent to the ventral surface of the brain, and often closely related to the optic nerves. They have a propensity to spread through the subarachnoid space with metastatic deposits to the walls of the ventricles and the basal cisterns.

Papillary Vs adamantinomatousCraniopharyngioma

Q.All are true regarding papillary craniopharyngioma except

a. typically found in the adult 

b. solid with extensive  calcification

c. often found within the third ventricle

c. encapsulated

d. typically enhance

ANS.—b

Papillary lesions are solid with no calcification . In distinction from their adamantinomatous counterpart, MR shows papillary craniopharyngiomas as solid lesions.  they are often situated within the third ventricle. These lesions demonstrate a nonspecific signal intensity pattern, without the characteristic hyperintensity on T1-weighted images of the cystic component of adamantinomatous tumors. Like all craniopharyngiomas, papillary lesions typically enhance.

On pathologic examination, papillary lesions do not show the features characteristic of the adamantinomatous variant, that is, the cholesterol crystals in a cystic component, wet keratin nodules, fibroinflammatory tissue, keratin, calcification, and nuclear palisades. In papillary lesions, there is extensive squamous differentiation.