Renal Metastasis from Squamous Cell Carcinoma of the Hypopharynx

We present a rare case of metastatic renal tumor originating from squamous cell carcinoma of the hypopharynx. A 67-year-old man treated with irradiation for hypopharyngeal carcinoma was referred to our hospital with gross hematuria and a left renal mass, which was delineated as a heterogeneously enhanced mass by CT scan. Left nephrectomy was performed, and the non-encapsulated mass was gray in color macroscopically. Histological examination of the specimen revealed alveolar proliferation of small cancer cells, which was consistent with the original tumor of the hypopharynx. The left renal tumor was diagnosed as poorly differentiated squamous cell carcinoma metastasized from the hypopharynx. The patient remains alive, with no evidence of disease, 8 months following left nephrectomy. This case was thought to be the first report of a renal metastasis from a hypopharyngeal carcinoma that was diagnosed clinically and treated with nephrectomy.