Primary angiosarcoma of the parotid gland arising from benign congenital hemangioma.

A case of malignant transformation of a benign congenital hemangioma of the parotid gland is presented. The malignant tumor occurred in a woman with a history of congenital hemangioma surgically removed 8 years previously. No radiotherapy had been administered at the time of primary excision. The recurrent tumor consisted of a large lesion occupying nearly all the parotid gland and infiltrating the surrounding soft tissues and overlying skin. Its histopathologic features were typical of epithelioid angiosarcoma. The vast majority of vascular lesions of major salivary glands are benign. However, pathologists should be aware of the remote possibility of malignant transformation in these lesions.