Clear-cell variant of squamous cell carcinoma in maxilla as primary lesion: A rare case

Oral squamous cell carcinoma with prominent clear-cell differentiation is a rare occurrence with incompletely understood etiology. We report a case of a 55-year-old male working in a steel factory presented with an ulcerated swelling on maxillary alveolar ridge, a rare site. Histopathology showed sheets of squamous cells with clear cell differentiation and features of malignancy. Periodic acid–Schiff and mucicarmine stains showed negative reaction. Immunohistochemical study using antibody for cytokeratin and epithelial membrane antigen revealed diffuse and intense positivity. The neoplastic cells showed complete negative reaction with antibodies for S-100 and vimentin.