Diagnosis: Squamous Cell Carcinoma
At first glance, the mass in the ear canal appeared similar to granulation tissue, which is inflammatory tissue produced by the body in the process of repairing injury or in response to infectious agents. Granulation tissue has a fleshy red appearance and bleeds easily with minor manipulation. It also has fragile capillaries—very small blood vessels easily injured by slight touching. Granulation tissue is easily breakable, can be suctioned freely, and can be mostly obliterated with chemical cauterization (silver nitrate). Its presence in a non-operated ear is uncommon.
Cholesteatoma can sometimes cause granulation at the level of the tympanic membrane superiorly or posterosuperiorly. Cholesteatoma, however, is rarely a cause of significant pain. Generally, if a patient with cholesteatoma has significant pain, we suspect some other underlying etiology.
Chronic otitis media is also capable of producing granulation tissue; however, it is a painless disease. The presence of pain in the setting of chronic otitis media likely indicates there is either another pathologic process or cause of the pain.
Otitis externa usually has significant pain associated with it. Granulation tissue in the presence of otitis externa is rare and is usually associated with malignant otitis externa, otherwise called skull base osteomyelitis. This condition occurs in the setting of significant immune suppression or diabetes. In the absence of an immune suppressing problem in our patient, it would be unlikely that skull base osteomyelitis would occur.
Another concerning sign was the facial paralysis. The patient stated that the episodes only lasted for a few hours, which is highly unusual for facial paralysis. The presence of an ear canal lesion combined with ear pain and intermittent facial paralysis indicates that something more ominous was occurring. Finally, mixed hearing loss indicated some involvement of the inner ear.
A closer look at the mass revealed prominent blood vessels within the mass in the ear canal. This indicated that the lesion was most likely not granulation tissue. Also, the patient had been suffering from significant pain for the past few months. In the presence of an ear canal mass and significant pain, further workup is warranted.
The patient's actual imaging CDs were obtained for review. This helps put into perspective the findings of the physical examination. Depending on the quality of the imaging obtained, further imaging studies may be ordered.
In the presence of mixed hearing loss, one possibility is a cholesteatoma that is eroding the horizontal semicircular canal. However, this generally would not be a painful disease. A quick review of the CT scan showed the horizontal canal was not involved at all in this disease process. The mass appeared to involve only the medial canal and sinus timpani (Fig. 3). The sensorineural component of the hearing loss was likely due to inflammatory mediators or the tumor crossing the round window membrane. That was possibly where the mass would have caused irritation to the descending segment of the facial nerve, leading to the intermittent facial paralysis.
A CT of the temporal bone showed the mass was limited to the posterior aspect of the middle ear and ear canal. An MRI with contrast showed the mass was enhancing entirely with the gadolinium contrast agent (Figs. 4 and 5). Diffusion-weighted imaging sequence did not reveal intensity, indicating that a cholesteatoma was much less likely. Contrast enhancement of the region indicated ample blood supply to it. While granulation tissue does enhance with gadolinium, granulation is usually due to a response to a primary process that is infectious or inflammatory.
In this case, the first step is to obtain a biopsy of the mass once imaging has been checked. The biopsy of a glomus tumor can cause massive bleeding. Though rare, an anomalous blood vessel (e.g., carotid or jugular) can present as a mass. Therefore, a mass that appears to be emanating from the middle ear should not be biopsied until imaging has been obtained.
In this patient, a biopsy was obtained and showed squamous cell carcinoma. Retracting the mass revealed the superior aspect of the tympanic membrane was normal. Carcinoma of the ear canal is rare, so diagnosis can be delayed significantly. It is not uncommon for patients with this type of cancer to be delayed in their care for months or even years. Treatment of squamous cell carcinoma of the temporal bone is primarily surgical. For early stage carcinoma, surgical excision has a cure rate of over 95 percent.
The surgical excision of this patient's tumor involved a lateral temporal bone resection, including removal of the external auditory canal, ear canal bone, tympanic membrane, malleus, and incus. Tumors that involve the middle ear require a subtotal resection of the temporal bone. These patients would need adjuvant radiation therapy, and the prognosis is significantly lower than a tumor limited to the ear canal. If the tumor involves the facial nerve, treatment would include resection and grafting of the facial nerve.
BONUS VIDEOS: VISUAL DIAGNOSIS
Read this month's Clinical Consultation case, then watch the accompanying videos from Hamid R. Djalilian, MD, to review the patient's imaging for yourself.
* Video 1. Axial CT images of the temporal bone showing the mass and its relationship with the cochlea.
* Video 2. Coronal CT images of the temporal bone showing the mass and its relationship with the vertical (mastoid) facial nerve.
* Video 3. Sagittal CT images of the temporal bone showing the relationship between the mass and the ossicles.
* Video 4. Axial diffusion - weighted imaging sequence of MRI showing no significant hyperintensity.
* Video 5. Axial T1 weighted post - gadolinium MRI images of the temporal bone demonstrating the enhancing mass.
* Video 6. Coronal T1 weighted post - gadolinium images showing the relationship of the tumor with the floor of the canal.
* Video 7. Video otoscopy of the patient's left ear.
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