High grade transformation of adenoid cystic carcinoma in the palate: Case report with review of literature

•High Grade Transformation of Adenoid Cystic Carcinoma in the palate is very rare tumor.•It represents a challenge in both diagnosis and management, with limited experience available.•The microscopic diagnosis and management is challenging, considering the sarcacity of the tumor. Adenoid cystic carcinoma (ACC) is a rare tumor developed in minor salivary glands, the palate being the most common site. Here, we report a case of a 58-year-old man with a 3-year-growing swelling in the right palate diagnosed with high grade transformation adenoid cystic carcinoma. The exam revealed a 4 cm large mass. A tumor resection with a radical neck dissection was performed. High grade transformation in adenoid cystic carcinoma is recently described by Cheuk et al. in 1999. This transformation has more aggressive behavior than conventional solid ACC and has usually been associated with recurrences, early distant metastasis, and greater mortality. The aim here is to highlight clinical, histopathological, therapeutic and prognostic aspects of high-grade transformation in ACC with literature review.