Epidermoid carcinoma arising in Warthin's tumor.

Warthin's tumor is a well-defined salivary gland neoplasm consisting of benign epithelial and lymphoid components. However, malignant transformation is extremely rare and the differential diagnosis of metastasis from an epidermoid carcinoma in Warthin's tumor is important. We present a case with epidermoid carcinoma arising in Warthin's tumor of parotid gland in a 48-year-old woman, and differential diagnosis is discussed.