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

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 myoepi-thelial 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.