Abstract
There is a wide variety of histological types of middle ear tumors, including glomus tumors, schwannomas, adenomas and hemangiomas. Among them, middle ear adenoma is an extremely rare disease that can arise anywhere in the middle ear cavity. It is often difficult to differentiate preoperatively because of its nonspecific clinical findings. The diagnosis of middle ear adenoma can be confirmed by histopathological examination. However, it is difficult to distinguish it histopathologically from carcinoid tumor of the middle ear, and they are considered synonymous with the disease.
We herein report a rare case of middle ear adenoma suspected as glomus tumor preoperatively. The patient was a 67-year-old female who presented with right pulsatile tinnitus and hearing loss. Otoscopic examination revealed a reddish and pulsatile mass in the tympanum through the tympanic membrane. CT demonstrated a mass localized in the meso- and hypotympanum without bone destruction. MR images revealed a tumor that was strongly enhanced by gadolinium. These findings led us to a diagnosis of glomus tympanicum tumor. Preoperative angiography findings revealed that the tumor was fed by the branch of the middle meningeal artery. The tumor was resected en bloc after embolization of the feeder vessel. The pathological diagnosis of the excised specimen was middle ear adenoma. No recurrence has been noted to date, 11 months after surgery.
The findings of this case suggest the necessity of including middle ear adenoma in the differential diagnosis, even if a tumor strongly suspected as glomus tumor is observed in the middle ear.
