Small Intestinal Metastasis of Renal Cell Carcinoma Discovered 16 Years Postoperatively

Abstract

A 73-year-old man had undergone right nephrectomy for right renal cell carcinoma in 2001. In 2010, he underwent partial thyroidectomy of a thyroid metastasis while undergoing postoperative chemotherapy, and in 2012, a bone metastasis in the right 6th rib was resected. Progressive melena and anemia were observed in November 2017, and small intestinal metastasis of renal cell carcinoma was diagnosed by double-balloon enteroscopy in January 2018. Partial small intestinal resection was performed the following month. Computed tomography in 2018 also showed that a small nodular shadow in the lung that had been identified in 2011, but for which a definitive diagnosis had not been made, had grown and formed multiple nodules, and this was also considered to be a lung metastasis of renal cell carcinoma. Small intestinal metastasis of renal cell carcinoma is comparatively rare, but if progressive anemia appears and gastrointestinal bleeding is suspected, then detailed examinations should be carried out with small intestinal metastasis borne in mind. Lung metastasis often appears before small intestinal metastasis, and if lung metastasis occurs, then subsequent follow-up must include monitoring for small intestinal metastasis for a certain period. This case suggests that the early detection and proactive surgical treatment of small intestinal metastasis may help prolong survival.