Potential Difficulties in Cytological Approach of Basal Cell Adenoma of Salivary Glands: The Experience of a Single Institution

Abstract

Objective: Basal cell adenoma (BCA) is an uncommon benign epithelial neoplasm of salivary glands, which was first described by Kleinsasser and Klein in 1967 and which derives its name from the monomorphic basaloid appearance of tumor cells. This tumor represents 1–2% of all salivary gland epithelial tumors; the most common site of occurrence is the parotid gland. It usually arises in adults over 50 years of age with slight female prevalence. Study Design: We analyzed 5 cases of parotid lesions investigated by fine needle aspiration cytology at a single institution between 2002 and 2018. Results: Our series was composed by 3 women and 2 men with a mean age of 62 years. The most important cytological criteria we observed were cohesive sharp-angled clusters of regular basaloid cells, palisaded by p63-positive myoepi­thelial cells, and bordered by basement membrane-like hyaline membrane in the absence of a myxochondroid stroma. Overall features were consistent with the diagnosis of BCA. Conclusions: Our aim is to highlight the cytological features of these rare lesions improving the awareness of cytological pitfalls of salivary gland basaloid neoplasms. Moreover, the goal of this paper is to add to the literature 5 additional cases of these unusual tumors.

Fine-Needle Aspiration Cytology of Cellular Basaloid Neoplasms of the Salivary Gland

“…In addition, loose aggregates of bland-appearing spindle cell stroma are often seen associated with the basaloid epithelial groups of BCA, a feature not typically seen in PA or ACC. 12,13 As with PA, ancillary studies are of limited utility in the diagnosis of BCA. Lymphocyte enhancer binding factor 1 (LEF-1), a downstream mediator of the WNT/b-catenin signaling pathway, is overexpressed in the nuclei of BCA but is typically negative in ACC on immunohistochemical stain.…”

“…In the differential diagnosis between ACC and BCA, S-100 expression favors ACC whereas LEF-1 expression favors BCA. 11,13,19 Basal Cell Adenocarcinoma.-Basal cell adenocarcinoma is a rare salivary gland malignancy, most commonly occurring in the parotid gland. It is considered the malignant counterpart of BCA.…”