Metachronous clear cell carcinoma of the tongue and kidney: a diagnostically challenging coincidence

Clear cell carcinomas (CCCs) account for 1% of carcinomas of the salivary glands. A 63-year-old woman presented with a painless, nonulcerated, nodular mass on the right side of the tongue, without palpable neck nodes. After excision and cryotherapy of the mass, the histologic evaluation revealed CCC. At the age of 55, she had undergone radical nephrectomy for CCC of the kidney which extended into the renal vein (pT3aN0). Although she had remained metastasis-free during the follow-up, the clear cell morphology raised the possibility of late lingual metastasis of the renal CCC. A clinical search for metastases, and a series of immunostainings and analysis of the von Hippel-Lindau gene were therefore performed on paraffin-embedded blocks of both tumors: Primary metachronous CCC of the tongue was diagnosed. This case illustrates the diagnostic challenge posed by CCC of the tongue if there is a history of CCC of the kidney.