Basaloid squamous cell carcinoma of the maxilla.

The study reports the first case of basaloid squamous cell carcinoma (BSCC) involving both the oral mucosa and the tuberosity area of the maxilla. The tumour showed many histological similarities to cases previously reported, though mitoses were not frequent. The immunoreactivity for cytokeratin, S-100, vimentin, Ki-67, p53, c-erbB-2 and bcl-2 was also investigated. Immunostaining for the bcl-2 protein showed a high extent of positive cells, although only a moderate staining intensity. Staining for c-erbB-2 was negative. The pathological findings and the immunoreactivity may indicate that BSCC is not as high a grade carcinoma as previously suggested. Additional studies are thus clearly needed to confirm or reject this impression.