Indolent Tumour of the Upper Lip: A Case of Lobulated Acinic Cell Carcinoma.

A majority of minor salivary gland neoplasms are encountered more frequently on the upper lip when compared to lower lip lesions. Although upper lip tumours generally turn out to be benign adenomas in the form of monomorphic adenomas and pleomorphic adenomas in 90% of the cases, rarely, a few indolent masses turn out to be carcinomas. Here, we report a long standing indolent upper lip swelling, which turned out to be a low-grade acinic cell carcinoma (ACiCa). Minor salivary gland tumours (MSGTs), considered as benign clinically, should be evaluated histopathologically for the confirmation of diagnosis, especially to rule out malignancy. Detailed, systematic histopathological and immunohistochemical (IHC) assessment for validation and confirmatory diagnosis is imperative. An added evaluation for tumour outcome with affirmative markers (DOG1), proliferative markers (Ki67), add value in diagnosis and prognostication of this tumour.