Metastasis of Clear Cell Renal Cell Carcinoma to the Maxillary Gingiva in a 75-Year Old Man: A Case Report

About 1% of all oral cancers are metastases of primary tumors elsewhere in the body and could be located in the soft tissue as well as in the jaw bones. Among all the primary tumors that arise below the level of the clavicle, renal cell carcinoma (RCC) is the third most common neoplasm according to metastasis in the head and neck region. Majority of the reported cases involve the jaw bones rather than the soft tissues. Here one case of metastatic RCC to the maxillary gingival is reported. The Patient was a 75 year-old man who chiefly complained about swelling in his anterior region of the maxillary gingiva. Excisional Biopsy was performed. Metastatic clear cell Renal cell carcinoma (CCRCC) was diagnosed by microscopic examination by demonstrating islands of cells separated from each other by thin fibrovascular septa, with stroma containing numerous sinusoid like vessels and immunohistochemistry (IHC) Staining (S-100, vimentin, EMA, CEA, CD10, CK7,TTF-1 and PSA). CT scan confirmed tumor in the right kidney. Nephrectomy and chemotherapy were performed but patient died 9 months after treatment as a result of metastases to brain and lung. CCRCC arise from renal tubular epithelium. Microscopically differential diagnosis for jaw tumors with clear cells includes a broad spectrum of tumors such as odontogenic tumors, salivary gland tumors and metastatic tumors. Generally, an immunohistochemistry panel consisting of S-100, vimentin, EMA.CEA, CD10.CK7, TTF-1 and PSA is useful to diagnose CCRCC from other clear cell tumors. Although IHC aids us in diagnosis, other paraclinical procedures like imaging should be done, to confirm the diagnosis.