POLYMORPHOUS LOW-GRADE ADENOCARCINOMA: CASE REPORT

Abstract

A 62-year-old White female patient presented to the stomatology clinic with a submucosal nodular lesion in a region of the lower right labial mucosa, asymptomatic, well delimited, circumscribed, movable, with a fibrous consistency, measuring 1 cm in diameter, with approximately 1 year of evolution. With the hypothesis of benign salivary gland neoplasm and benign mesenchymal neoplasm, an excisional biopsy was performed. Histologically, proliferation of cells organized in nests, ducts, and cords was observed, showing pale nuclei and evident nucleoli. The presence of mucous cells and cribriform areas and extracellular matrix, sometimes fibrous and other times hyaline, was noted. Immunohistochemically, cells were positive for cytokeratins 7 and 14, S-100, and p63 and focally positive for smooth muscle actin. The cell proliferation index measured by Ki-67 was less than 5%. In view of the clinical and microscopic characteristics, the diagnosis of low-grade polymorphous adenocarcinoma was closed. The patient was referred to the head and neck surgeon.