Metastatic renal cell carcinoma mimicking pituitary adenoma: case report.

A 54-year-old man, with a past history of renal cell carcinoma, presented with bitemporal visual field defect, hyponatremia, and diabetes insipidus. Endocrinological examination revealed panhypopituitarism. Computed tomography and magnetic resonance imaging showed an intrasellar mass with suprasellar extension. The initial radiological impression was pituitary adenoma. The tumor was decompressed via the transsphenoidal route. Histological examination revealed metastatic renal cell carcinoma. The clinical characteristics of metastatic pituitary carcinoma appear to be panhypopituitarism, and neuroimaging findings of strong enhancement of the tumor and bony destruction without marked sellar enlargement.