Intra- and suprasellar germinoma mimicking a pituitary adenoma--case report.

A 25-year-old female presented with amenorrhea and bitemporal hemianopsia without diabetes insipidus due to an intra- and suprasellar dumbbell tumor. The preoperative and operative diagnosis was pituitary adenoma, but the histological diagnosis was germinoma. Differential diagnosis between germinoma and pituitary adenoma based on computed tomograms and magnetic resonance (MR) imaging features and signal intensity characteristics was difficult in this patient. An enhanced mass posterior to the normal pituitary gland on the mid-sagittal MR image normally indicates an intrasellar germinoma rather than a pituitary adenoma, but this finding was equivocal in our patient.