Glomus tympanicum tumors (also known as paragangliomas of the middle ear) are highly vascular, benign (non-cancerous) tumors that arise from paraganglia in the middle ear. Conductive hearing loss is common due to the tumor occupying space within the middle ear and preventing transmission of sound through the eardrum and ossicular (hearing bone) chain. Additionally, pulsatile tinnitus occurs frequently due to the vascular nature of these tumors. Very large glomus tympanicum tumors may cause vertigo (feeling that the world around you is spinning when you are not moving), facial paralysis and sensorineural hearing loss. Rarely, hormones may be manufactured by the tumor, which cause rapid heartbeat, headaches, flushing, excessive sweating and diarrhea. Smaller glomus tympanicum tumors may not produce any symptoms but can be found incidentally as reddish mass lesions under the eardrum.
Glomus tympanicum tumors are first detected/evaluated in the office by a thorough microscope (binocular) examination of the ear. Due to the highly vascular nature of the tumor, a reddish mass is typically observed behind the eardrum. Imaging studies, including CT scans, MRI scans and MR angiography (to get more information about the vascular properties of the tumor), are indicated. Three treatment options exist for glomus tympanicum tumors and recommendations are based on the individual properties of each tumor. Because these tumors are slow growing, observation using serial imaging is an option if the tumor is small and not causing troublesome symptoms. Surgical removal ranges from relatively simple transcanal approaches to much more complex mastoid and petrous operations depending on the size, location of the tumor and extent of other structures involved. In many cases, hearing and facial nerve function can be preserved with surgery. Lastly, radiation is an option that may halt the growth of the tumor by cutting off its blood supply, but the tumor is not removed.