Primary Squamous Cell Carcinoma of the Excretory Duct of the Submandibular Gland: A Rare Case

摘要

Primary Squamous Cell Carcinoma (SCC) of the salivary glands is a very rare disease and establishing the true origin of an SCCmanifesting in a salivary gland is always a daunting task, due to the natural proximity of salivary glands to surface epithelia. Theaim of this report is to describe and discuss an SCC originating from the excretory duct of the submandibular gland with an unusualhistological papillary appearance. A 39-year-old male presented with a slow growing mass in the ?oor of the mouth, which wasclinically nodular, exophytic and ulcerated. Histological examination revealed a predominantly papillary architecture surroundingan intact salivary duct, which showed mucicarmine-positive material and no cell atypia. The duct was in a continuum with theneoplastic tissue, disposed as sheets of basaloid cells with foci of dysplastic squamous epithelium with minimal keratinization. Thelesion was positive to CK14 throughout the parenchyma, CK7 in the luminal cells of ductal structures, CK13 in rare epidermoid areasand generally to AE1/AE3, highlighting foci of keratinization. The case reported herein is a very rare neoplasm in an unprecedentedintraoral site, which emphasises the importance of histochemistry and immunohistochemistry in the diagnosis of rare lesions.