Intra- and suprasellar schwannomas with hypopituitarism – report of 2 cases

The differential diagnosis of intrasellar lesions is extensive. Pituitary adenomas account for the majority of primary intrasellar neoplasms. Other hormonally inactive tumors are less common in this location but may clinically mimic nonsecretoring pituitary adenomas due to mass effects and compression of neighbouring structures. Hypopituitarism and visual field defects are typically found. The most common non-pituitary intrasellar neoplasms are craniopharyngeomas, germ cell tumors, meningeomas, chordomas, and pituicytomas. Schwannomas of the sellar region are extremely rare and usually not included in the differential diagnosis of intra- and parasellar lesions. Here, we present two cases of intra- and suprasellar tumors of adenoma-like appearance. Histological examination of surgical specimen revealed tumors consisting of spindle-shaped cells of uniformly high cellularity with no evidence of hypocellular areas, diagnosed as cellular schwannomas. True intrasellar schwannomas without involvement of cranial nerves have only been reported in four cases to date, their origin is under debate.

In summary, schwannomas are uncommon intrasellar neoplasms which can clinically and radiologically mimic nonsecreting pituitary adenomas. Vascularisation may pose a challenge to the neurosurgeon regarding radical removal of the tumor. Histopathologically, these spindle cell tumors must be distinguished from fibrous meningioma, melanocytoma, and pituicytoma.