Metastasis of renal clear-cell carcinoma to the oral mucosa, an atypical location.

The majority of cases of metastatic tumors involve the mandible and some the maxilla but they are considerably less common in intraoral soft tissues. In addition, the primary tumor is known in the majority of cases; although in one-third of such cases, metastasis is the first clinical manifestation. The most common primary tumors metastasizing to the mouth are lung carcinoma in men and breast carcinoma in women. An oral metastasis implies a serious prognosis, as in the majority of patients there is multiple organ involvement at the time of diagnosis. We present the case of a 52-year old patient with renal pathology who came to the emergency room due to a rapidly increasing gingival tumor. With the provisional clinical diagnosis of a pyogenic granuloma,the tumor was excised. Subsequent anatomopathological analysis revealed a tumor metastasis compatible with clear-cell carcinoma, and its renal origin was confirmed by means of immunohistochemical techniques.