Accuracy of frozen section diagnosis of the salivary gland.

Three hundred and one salivary gland lesions (162 benign, 72 malignant, and 67 benign non-neoplastic) of 677 cases were evaluated by use of intraoperative frozen sections by 66 pathologists. In seven patients, the diagnosis was deferred for permanent sections. In four cases (1.3%), the diagnosis at permanent section changed from one category of benign tumor to another, and in five cases (1.7%), from one category of malignant tumor to another. In four tumors, a frozen section diagnosis of benign was changed to malignant on permanent sectioning; all four involved acinic cell carcinomas. Only two tumors were incorrectly diagnosed as malignant. We conclude that diagnoses of most salivary gland lesions based on frozen section examination are reliable and accurate. However, the literature does indicate that caution should be exercised when malignant tumors are dealt with.