Slow-Growing Pituitary Metastasis from Renal Cell Carcinoma: Literature Review.

Background: Tumor metastasis to the pituitary is rare, most commonly reported with either breast or lung cancer metastasizing to the neurohypophysis. Pituitary metastases of renal cell carcinoma (RCC) are by contrast infrequently described even within this scarce literature. We present an illustrative case of RCC pituitary metastasis 15 years after radical nephrectomy for primary disease and a review of the published literature.

Case Description: A 69-year-old female was diagnosed with a large sellar mass with suprasellar extension. The initial radiologic diagnosis was most in keeping with pituitary macroadenoma, although prominent vascular flow voids were noted. Endoscopic endonasal transsphenoidal adenectomy was challenging on account of significant intraoperative hemorrhage from an unusually vascular tumor. Pathologic examination supported a diagnosis of metastatic clear cell renal carcinoma. Literature review identified 41 cases of RCC pituitary metastasis since 1984. The mean age at time of diagnosis with pituitary metastasis was 59.5 years (range 35-81 years, 73% male). Pituitary metastasis was the initial presentation of RCC in 10 patients. The median time from RCC diagnosis to pituitary metastasis was 1 year (range 0-27 years). Surgical resection was performed for 30 patients, of which 47% reported a highly vascular tumor.

Conclusions: We highlight the potential for delayed metastasis to the pituitary to masquerade as a macroadenoma. Imaging consistent with rich vascularity should bring the diagnosis of RCC metastasis into the differential and is important to note when planning surgical resection in such cases.