Extraordinarily Large Renal Cell Carcinoma With Metasynchronous Neuroendocrine Tumor of the Ileocecal Valve: A Rare Presentation of Disease.

A 71-year-old female presented with a large, protuberant abdominal mass, and was found to have both a left renal mass and a biopsy-proven neuroendocrine tumor of the ileocecal valve. Ultimately, right hemicolectomy revealed a well-differentiated and low-grade neuroendocrine tumor of the ileocecal valve, whereas left radical nephrectomy revealed a 23 cm × 22 cm × 15 cm renal cell carcinoma, chromophobe-type (RCC-CT) weighing 3564 g. RCC-CT represents a small portion of diagnosed RCC, and generally portends a more favorable prognosis than other variants. Modern reports of renal tumors exceeding 20 cm are exceedingly rare. In spite of massive size, favorable histology may allow for surgical cure.