The Youngest Case of Metachronous Bilateral Acinic Cell Carcinoma of the Parotid Gland: A Case Report and Literature Review.

INTRODUCTION: Acinic cell carcinoma (ACC) is a low-grade malignant salivary neoplasm that represents 17% of all salivary gland malignancies. It has a tendency to affect young individuals, especially females. ACC mainly originates in the parotid gland and has a potential for recurrence and metastases. Rarely, ACC can affect both parotid glands in a single individual. A bilateral ACC of the parotid gland could either present as a synchronous or a metachronous tumor. Case Report. Our patient is a 19-year-old female known case of ACC of the right parotid gland. The tumor was resected in December 2017. After 3 years, she presented with a left parotid pain and swelling, which raised the suspicion of a contralateral metachronous tumor of the left parotid gland. In September 30, 2020 we proceeded with ultrasound-guided fine needle aspiration of the left intraparotid lesion, and the results turned out to be consistent with ACC. Here, we report a case of a 19-year-old female presenting with metachronous bilateral ACC of the parotid gland with an interval of 3 years, which is the 6th of its kind in the literature and the youngest amongst them.

CONCLUSION: Despite the rareness of metachronous occurrence of bilateral ACC of the parotid gland, it is still encountered in the medical practice. Here, we are highlighting the importance of follow-up with a periodic clinical and radiological examinations, bearing in mind the contralateral nonaffected parotid gland.