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.