An Exquisite Case Report of Follicular Variant of Acinic Cell Carcinoma of the Parotid Gland With Review of Literature

Acinic cell carcinoma (ACC), previously called acinic cell tumor, is an uncommon malignant neoplasm that tends to recur locally without proper treatment measures. This low-grade neoplasm has four histological subtypes. We hereby report a case of a follicular variant of ACC, which is a rare subtype. A 20-year literature search encompassing this variant of ACC of the parotid region was also performed, which showed four reported cases. A 60-year-old woman reported to our college, Kalinga Institute of Dental Sciences, with the chief complaint of pain and swelling in her upper right back tooth region for the past three months. Upon incisional biopsy, histopathological examination revealed a follicular variant of ACC. Further, immunohistochemistry was also performed using markers such as DOG-1, CK7, S-100, and thyroglobulin, which showed CK7 marker positivity. Subtotal parotidectomy was performed and the tissue was sent for histopathological analysis. Although ACCs are slow-growing and indolent in character, they can frequently recur locally decades later and spread to distant organs. Long-term follow-up is necessary following therapy as ACC has a noticeably high propensity to relapse and create latent metastases.