Synchronous squamous cell carcinomas of the esophagus and renal pelvis

A 55-year-old man was incidentally diagnosed with a superficial squamous cell carcinoma of esophagus. However, the systemic survey with FDG PET/CT revealed a picture of more advanced disease because of the regional lymph node metastases and a suspected distal metastasis in the left renal pelvis, which was somewhat strange for a small superficial esophageal cancer. Subsequently, the renal pelvic lesion was confirmed as squamous cell carcinoma. However, a primary tumor rather than metastasis in the renal pelvis was considered according to the histologic characteristics and radiologic findings.