Pigmented oral squamous cell carcinoma: a case report and brief review of the literature.

Melanin impregnation in squamous cell carcinoma (SCC) is an uncommon histological finding. Rare nonmelanocytic entities were previously described as having melanocyte colonization. A 57-year-old Brazilian woman was referred with a pigmented lesion in the lower lip and alveolar ridge with a prior clinical diagnosis of melanoma. The incisional biopsy of the tumor revealed an SCC with strong colonization of melanocytes in the stroma. The authors report a case of an unusual SCC variant and a brief review of the literature.