A Case of Middle Ear Adenomatous Neuroendocrine Tumors: Proposal of a Staging System

Abstract

A 49-year-old man visited a local otolaryngology clinic with left hearing loss. He was diagnosed as left middle ear tumor and referred to us. The tumor was protruding from the left tympanic membrane. Computed tomography (CT) revealed thickening of the tympanic membrane, space-occupying lesions in the middle ear cavity and mastoid air cells, and no bone destruction in the left middle ear. Magnetic resonance imaging confirmed the CT findings, and the lesions were hyperintense on T1- and T2-weighted imaging. He was diagnosed as middle ear adenomatous neuroendocrine tumor (MEANT) with a pathological result. The patient underwent postauricular approach and canal wall-down mastoidectomy. The tumor occupied the mastoid air cells and extended into the middle ear mucosa. To prevent perilymphatic fistula, the tumor was excised as extensively as possible, while preserving the tumor around and adjacent to the stapes footplate. MEANT is extremely rare and long-term follow-up is necessary due to be potential for tumor regrowth or recurrence. Herein, we propose a new staging system for MEANT.