Immature teratoma originating from the pituitary gland: case report

Recently, it has been suggested that the primary site of suprasellar germinomas is the neurohypophysis, but nongerminomatous germ cell tumors originating from the pituitary gland have been rarely reported.

A 27-year-old man presented with panhypopituitarism, bitemporal hemianopsia, and mild right oculomotor nerve paralysis. Diabetes insipidus was not observed. The tumor was shown by magnetic resonance imaging to extend and invade bilateral cavernous sinuses, sellar and clival dura mater, and the sphenoid sinus mucosa.

Transsphenoidal removal yielded a diagnosis of immature teratoma. Serum alpha-fetoprotein was prominently elevated. Magnetic resonance imaging and surgical findings of the superiorly displaced residual pituitary gland strongly suggest the pituitary origin of this rare tumor.

In contrast to the neurohypophyseal germinomas, nongerminomatous malignant germ cell tumors originating from the pituitary gland tend not to be associated with diabetes insipidus and thus mimic adenomas. Evaluation of the tumor markers is necessary in young patients with cavernous sinus syndrome and invasive pituitary tumors with heterogeneous intensity revealed by magnetic resonance imaging.