Hyalinizing Clear Cell Carcinoma of the Base of Tongue Mistaken for Benign Lesion: A Case Report

Abstract

Hyalinizing clear cell carcinoma (HCCC) is a rare, low-grade malignant tumor of the salivary gland. It usually originates from the minor salivary gland, with the most common site being the palate, followed by the lips and the buccal mucosa. The occurrence of HCCC at the base of the tongue (BOT) is extremely uncommon, thus it must be differentiated from other malignant clear cell tumors. Immunohistochemistry is a useful tool to make an appropriate diagnosis. To obtain the best prognosis for HCCC, complete surgical resection is necessary. Here we report a case of a 47-year-old male with a benign-looking neoplasm in the right BOT, presenting with throat discomfort. A simple excisional biopsy revealed proliferative nests of clear cells within a hyalinized fibrous connective tissue. The final diagnosis by immunohistochemistry was HCCC with a positive resection margin. Re-operation secured a safety margin, and the lesion was completely resected.