Salivary gland cystadenocarcinoma: Rare neoplasm in buccal mucosa.

A 72-year-old female was referred for diagnosis of a lesion located in the right buccal mucosa, with duration unknown. At intraoral examination, the lesion appeared as a well-delimited, mobile, and submucosal nodule. A benign mesenchymal neoplasm was the main hypothesis of diagnosis. Histopathological analysis revealed salivary gland neoplasm formed by atypical cells often arranged in microcystic structures, with frequent intraluminal papillary projections. The tumor cells presented positivity for CK7 and negativity for CK20. Based on these features, the diagnosis of cystadenocarcinoma was established. The patient was submitted to wide surgical resection. No recurrence was observed after 48 months. Although rare, cystadenocarcinoma should be considered in the differential diagnosis of oral submucosal nodules.