Acinic cell carcinoma of minor salivary glands.

Three cases of acinic cell carcinoma of minor salivary glands, located respectively in the larynx, base of the tongue, and right tonsil, were encountered at the Section of Pathology of the ENT Department of the University of Padua between 1974 and 1978. Such neoplasms arising in minor salivary gland tissue are extremely rare, but may be found in all sites containing normal or aberrant salivary gland tissue. The histological and histochemical characteristics of the tumour are discussed together with the differential diagnosis from other neoplasms, particularly clear-celled tumours such as glycogen rich adenocarcinoma, mucoepidermoid carcinoma, metastatic clear cell renal adenocarcinoma and clear cell squamous carcinoma. In general, acinic cell carcinoma can be defined as a tumour of low-grade malignancy, though not too rarely it may recur and occasionally metastasize.