Parotid cysts. An analysis of 16 cases and suggested classification.

Cystic lesions, greater than 8 mm in diameter, were found in 16 of 183 surgically excised parotid glands over an 8 yr period. Of these 16 cysts, 9 had developed in parotid neoplasms, usually of Warthin type. The remaining 7 were not associated with neoplasms and 5 were unilocular. The epithelial lining of non-neoplastic cysts was squamous in all but one case, and there was lymphoid tissue in the walls of 3 cysts. On the basis of these findings and a review of the literature, a morphological classification of parotid cysts is proposed. To the surgical pathologist, the major problems in dealing with parotid cysts are the recognition of associated neoplasms and of those cysts likely to have accompanying congenital abnormalities.