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

Abstract

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

Keywords

• : immunohistochemistry
• malignancy
• salivary gland tumours
• wharton’s duct