Discussion
Coexisting pathology of the temporal bone has been previously reported. One report demonstrates that 11 percent of temporal bones were found to have more than one coexisting pathologic finding such as otitis media, otosclerosis, endolymphatic hydrops, labyrinthitis, and cancer when studied post-mortem in an otopathology lab [4].
Our case demonstrated a nonclassical presentation of a Glasscock-Jackson type 4 glomus tympanicum tumor with a coexisting cholesteatoma. The atypical polypoid appearance of the glomus tympanicum tumor has been previously described where the tumor extending into the external auditory canal mimicked a polyp covered by squamous epithelium [5]. Our patient did not present with pulsatile tinnitus or conductive hearing loss, and in fact had a profound sensorineural hearing loss with high frequency nonpulsatile tinnitus. This atypical presentation is likely due to the glomus tumor’s late diagnosis. It is possible the delay of diagnosis with lack of treatment allowed the glomus to enlarge extending into the ear canal resulting in trapped squamous epithelium causing a cholesteatoma to form. The cholesteatoma likely then contributed to a presentation of chronic infectious otorrhea. The sensorineural hearing loss may be secondary to the long-standing infection as previously noted in a correlative study [6]. Another study demonstrated that sensorineural hearing loss in such presentation could be due to a cochlear fistula caused by chronic otitis media with cholesteatoma [7]. It is likely the patient may have had an improved hearing result if a diagnosis and treatment had occurred prior to the onset of sensorineural hearing loss.
The glomus tumor was diagnosed in the office only after temporarily clearing the infectious otorrhea using antibiotics. Cholesteatoma coexisting with a glomus tympanicum has only once been previously reported in literature representing a rare clinical entity [8]. Similarly, in our case the cholesteatoma was found intraoperatively during the canal wall down mastoidectomy. Diffusion weighted MRI did not assist in differentiating the glomus tumor from the cholesteatoma in this case. The overall size of the glomus was considerably more than the cholesteatoma likely making this differentiation difficult on imaging.
Cholesteatomas tend to have some similarities with glomus tumors such as being locally destructive, nonmetastasizing, and causing conductive hearing loss. Cholesteatoma’s unlike glomus tumors tend to present with chronic otorrhea similar to our case. Extensive glomus tympanicum presentation where the neoplasm extends into the external auditory canal with coexisting chronic infectious otorrhea should have a high clinical suspicion for a cholesteatoma.