Acinic cell carcinoma: a clinicopathologic study of thirty-five cases.

A clinicopathologic study of 35 cases of acinic cell carcinomas is presented. Complete follow-up information was available on 31 patients (average period, 7-5 years). The malignant potential of these neoplasms is affirmed by observations that metastases (local and distant) occurred in nine patients and that eight patients died as a consequence of their carcinoma. Retrospective classification of the carcinomas into high and low grade lesions correlated well with ultimate biologic behavior but is unlikely to be successful in an intra-operative (frozen section) mode. This limitation is due to: (a) sampling limitations at the time of primary surgery and (b) the malignant behavior of the occasional low grade carcinoma. Histologic features characterizing high grade carcinomas are local aggressive infiltration and areas of the tumor that appear analogous to the embryonic and post-embryonic terminal tubules and intercalated ducts. The best opportunity for cure of these neoplasms lies in their complete surgical removal at the time of initial treatment. For this, a total parotidectomy is the procedure of choice. Enucleation and local excision is to be condemned.