Limitations of pathologic diagnosis in salivary gland tumors.

The pathologist's diagnosis of mucoepidermoid tumor, acinic cell tumor, or oncocytoma may lull the surgeon into a false sense of security about the biologic potential of these tumors. A small percentage of low-grade mucoepidermoid carcinomas pursue an aggressive biologic course leading to metastases and death of the host. There are also acinic cell tumors and oncocytomas which biologically behave malignantly, metastasizing and causing death. Histologically and cytologically, these malignant varieties cannot be separated from those which pursue a benign course and would theoretically require only conservative excision. It is suggested that when the surgeon receives one of these three diagnoses, the extent of surgical resection be determined by the patient's clinical presentation, as well as knowledge of the tumor's potential, rather than the histopathologic appearance. Evidence from the literature is presented to support this concept.