Malignant degeneration of pleomorphic adenoma--clinical implications.
BACKGROUND
The incidence of carcinoma arising in a pleomorphic adenoma is reportedly between 1.4% and 6.3%. Malignant degeneration is often associated with a prolonged history of untreated or recurrent pleomorphic adenoma.


METHODS
Two patients with malignant parotid carcinoma that arose from benign pleomorphic adenoma are reviewed.


RESULTS
Both patients exhibited a prolonged history of pleomorphic adenoma apparently persistent after initial inadequate surgery. Surgeries were performed 37 and 12 years before development of malignancy.


CONCLUSIONS
The phenomenon of malignant carcinoma arising from benign pleomorphic adenoma is an important issue. The occurrence of these malignant carcinomas emphasizes that aggressive treatment of primary and recurrent mixed tumors is necessary.
Duck
S W
SW
St Joseph Hospital, Atlanta, GA.
McConnel
F M
FM
D000230:Adenocarcinoma / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009373:Neoplasms, Germ Cell and Embryonal / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D016609:Neoplasms, Second Primary / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D010307:Parotid Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery