Glomus tympanicum

Ear, Nose & Throat Journal, June, 2007 by Joe Walter Kutz, Jr., William H. Slattery, III

A 24-year-old woman presented with a 3-year history of left aural fullness and pulsatile tinnitus. She denied hearing loss, vertigo, and otalgia. Her personal history was negative for relevant head trauma and ear infection, and she had no family history of hearing loss or paraganglioma. Otoscopic examination of the left ear detected a red mass in the hypotympanum (figure). The mass was medial to the umbo of the malleus and inferior to the stapes and incus. The mass blanched on pneumatic otoscopy. Air-and bone-conduction findings were within normal limits. The glomus tympanicum was removed via an extended facial recess approach. No intraoperative complications occurred, and gross removal of the tumor was achieved. Findings on postoperative audiometry were unchanged from preoperative levels.

Glomus tympanicum is an uncommon paraganglioma that arises from the promontory of the cochlea. The blood is supplied by the inferior tympanic branch of the ascending pharyngeal artery. The most common presenting symptom is pulsatile tinnitus. The growth of the tumor follows the path of least resistance. Involvement of the ossicles causes a conductive hearing loss. With extension into the mastoid antrum, the facial nerve may become involved. Growth through the tympanic membrane may cause bloody otorrhea or otalgia. Growth through the hypotympanum may result in exposure of the jugular bulb and later the carotid artery.

Physical examination will reveal the presence of a red mass behind an intact drum. Blanching of the mass on pneumatic otoscopy is commonly referred to as Brown's sign, and it is pathomnemonic for a glomus tumor. Treatment should include removal of the entire tumor; a transcanal approach can be used for small tumors, but a postauricular approach with an extended facial recess may be required for larger tumors. Bleeding is often brisk, so the tumor should be fully exposed before removal is attempted. Gross total removal of the tumor is desirable because recurrence is possible.