Metastatic Sarcomatoid Renal Cell Carcinoma: A Journey From the Kidney to the Gingiva

Abstract

Oral metastatic lesions are very rare and are often diagnosed at a later stage, complicating treatment. Renal cell carcinoma (RCC) is the third most frequent neoplasm to metastasize to the oral cavity, following breast and lung cancers. These metastatic lesions are usually asynchronous and develop after the initial diagnosis, affecting the overall survival rate. This report describes a known case of RCC with a growth in the mandibular gingiva. Multiple pulmonary and femoral metastases appeared five years after the initial renal lesion. The gingival growth was excised and referred for histopathological examination, which revealed a pleomorphic sarcomatoid cellular morphology. Immunohistochemistry with an array of markers led to the diagnosis of sarcomatoid RCC, a rare high-grade tumor. This case underscores the importance of detailed history-taking, interpretation of clinical findings, and emphasis on histopathological examination to arrive at a conclusive diagnosis.