ORAL METASTASIS OF RENAL CELL CARCINOMA

Renal cell carcinoma (RCC) is the third most common neoplasm to metastasize to the oral cavity, eventually as the first manifestation of the disease. An otherwise healthy 76-year-old man was referred for evaluation of a 5 × 4 cm reddish, lobulated, and ulcerated mass located in the upper posterior gingiva. A well-defined lytic lesion in the left maxilla was revealed by computerized tomography. Microscopic examination revealed sheets of neoplastic clear cells arranged in an alveolar pattern, with many central blood vessels. Tumor cells were positive for CD10 and epithelial membrane antigen and negative for CK7, CK20, and vimentin. The final diagnosis was oral metastasis of RCC. The patient was referred to an oncologist for clinical and imaging check-up, which showed uptake in the liver and kidney. RCC was confirmed after incisional biopsy of the kidney. Gingival metastasis of RCC may present as a clear cell tumor in patients who are unaware of their cancer.