Pigmented mucoepidermoid carcinoma with spindle cell differentiation.

Mucoepidermoid carcinoma is the most common malignant salivary gland tumor of children and adults, showing diverse histopathologic features. Mucoepidermoid carcinoma with both melanin pigmentation and spindle cell differentiation has not been previously reported. We report the first documented case of pigmented mucoepidermoid carcinoma with spindle cell differentiation in a 34-year-old woman who presented with a swelling of the floor of the mouth.