[Metastatic renal tumor from oral floor cancer: a case report]

A 61-year-old man with oral floor cancer (adenoid cystic carcinoma, T2N0M1) was treated with systemicc hemotherapy and radiation therapy at the department of dentistry and oral surgery in our hospital. He had three lung metastases and renal tumors detected by screening computed tomography. The oral floor cancer responded to the treatment to achieve partial response. However, lung and renal metastases did not respond to chemotherapy. Then, the patient was referred to our clinic to rule out the possibility of lung metastasis from renal cell carcinoma. Laparoscopic left nephrectomy was performed and pathological examination on the renal lesions revealed adenoid cystic carcinoma, which had identical histopathological features to the oral floor cancer. To our knowledge, this is the first report of metastatic renal tumor from oral floor cancer (adenoid cystic carcinoma).