Sinonasal Inverted Papilloma Associated with Adenoid Cystic Carcinoma

Abstract Inverted papilloma is the most common benign tumor of the paranasal sinuses with the possibility of malignant transformation. On the one hand, adenoid cystic carcinoma (ACC) is a rare malignant neoplasm that arises from the secretory glands. Sinonasal ACC accounts for 10%–25% of all head and neck ACC. This neoplasm is defined by its distinctive histologic appearance. Surgical resection, whenever possible, is the mainstay therapy. An association between inverted papilloma and malignancy is controversial. A synchronous carcinoma has been established at diagnosis in 3.3%–11% of cases, and the risk of metachronous carcinoma is