Basal cell adenocarcinoma of the soft palate: A closer look for an exceedingly rare salivary gland tumor.

ABSTRACT

Basal cell adenocarcinoma (BCAd) is an extremely rare primary biphasic carcinoma of the salivary glands with few well-documented cases reported in the literature. Herein, we report a rare case of a 44-year-old male patient who presented an oral medicine service with an erythematous nodular lesion on the soft palate, measuring 1.5 cm in its largest diameter, with a 5-year duration. The clinical diagnosis was pleomorphic adenoma, and an excisional biopsy was performed. Histopathological analysis revealed a biphasic infiltrative tumor composed of a mixture of central ductal cells and abluminal basal cells with slight atypia arranged in solid, trabecular, tubular and cribriform growth patterns in a loose stroma. The peripheral cells show a palisading arrangement with round hyperchromatic nuclei and scanty cytoplasm. Occasional mitotic figures were seen. Few spindle-shaped cells suggestive of myoepithelial cells were present in the stroma surrounding the basaloid tumor nests. The diagnosis was BCAd. The patient was referred to a head and neck service and has been followed up for 8 months with no signs of recurrence. In conclusion, although the diagnosis of BCAd can be challenging due to its rarity and morphological overlap with other salivary gland lesions, a meticulous morphological assessment is key for accurate diagnosis, especially in cases originating from minor salivary glands. Surgical excision with a wide safety margin is the treatment of choice and long-term follow-up is recommended to monitor possible recurrences.