Papillary cystadenoma: a rare tumor of the minor salivary glands.

Papillary cystadenoma of the minor salivary glands is a rare benign neoplasm that clinically resembles mucous cysts. Characteristic histological features are diagnostic. However, salivary gland histology is particularly difficult to interpret. Primarily, as further clinical and histological differential diagnoses have to take into account the well-differentiated cystic mucoepidermoid carcinoma and the papillary cystic type of acinic cell carcinoma, both malignant neoplasms of the salivary glands. We report on a 39 year old female with a bluish cystic lesion at the buccal mucosa, which occurred 14 years after the excision of a similar appearing, histologically proven mucous retention cyst at the same location. The histology of this tumor, however, revealed a papillary cystadenoma. Although rare, benign and malignant salivary gland neoplasms occur in minor salivary glands, and are clinically indistinguishable from mucous retention cysts. The dermatologist should be familiar with these differential diagnoses, since different therapeutic consequences result from an early diagnosis obtained by excision and histological examination of oral cystic tumors.