DEDIFFERENTIATED ACINIC CELL-CARCINOMA OF THE PAROTID-GLAND - A DISTINCT RARELY DESCRIBED ENTITY

A case of dedifferentiated acinic cell carcinoma of the parotid gland is presented. A 46-year-old man presented with a parotid gland mass. A t surgery the tumor was found adherent to the temporal bone and cervic al adenopathy was present, Treatment included radical parotidectomy an d intraoperative radiotherapy, Histologically, the tumor was a composi te of a usual low-grade acinic cell carcinoma and high-grade, poorly d ifferentiated carcinoma. Cervical lymph node metastases were composed entirely of high-grade carcinoma. Immunohistochemically, both low- and high-grade malignant components were negative for p53 oncoprotein exp ression. Moreover, polymerase chain reaction and nonisotopic single-st randed conformational polymorphism analyses were consistent with a ger m line configuration of the p53 gene, exons five through eight, in bot h low- and high-grade elements of the tumor, The literature on this un usual variant of acinic cell carcinoma is reviewed, HUM PATHOL 28:869- 873, Copyright (C) 1997 by W,B, Saunders Company.