[Acinic cell adenocarcinoma of the lip]

The variable histological appearance of acinic cell carcinoma coupled with its uncommon occurrence account for considerable diagnostic difficulties. We present the case of a 68 years old women, with a salivary cyst localised in the upper lip. The tumour mass was excised, fixed in formaline, embedded in paraffin and the sections were stained with Haematoxylin-Eosin, PAS-Haematoxylin, PAS-Alcian blue and Perls. The tumour was nodular, well circumscribed, with a cystic appearance on the cut surface. Microscopically, the tumour had a papillary-cystic growth, with one large cystic space lined by epithelium of variable thickness and branching projections of epithelium occupying a large portion of the cyst's lumen. Different cellular features were recognised in the tumour, with the presence of both serous and mucous acinar differentiation. Also, vacuolated cells were present in a large number. Acinic cell adenocarcinoma is a malignant epithelial neoplasm in which the neoplastic cells demonstrate not only serous acinar differentiation. The clinical and histopathological findings are discussed in the light of the literature.