[Clear cell adenocarcinoma of the tongue. Coincidence or distant metastasis?]

Malignant tumors of the salivary glands are rare, they account for less than 0.5% of all malignancies and for 5% of cancers of maxillofacial regions. Clear cell adenocarcinoma represents 1% of malignant tumors of the salivary glands. The present case involved a 63-years-old Hungarian woman with a painless, non-ulcerated, nodular mass on the right side of the middle part of the tongue. Her past medical history included right nephrectomy of renal cell carcinoma, seven years before the tongue tumor. The initial orofacial clinical examination suspected lipoma, neurinoma or distant metastasis of the renal cell carcinoma. The histomorphological analysis of the resected tongue tumor showed similar clear cell adenocarcinoma mimicking the phenotype of renal cell carcinoma but detailed immunohistochemical analysis proved the primary origin of tongue indicating second primary metachronous malignant tumor.