Symptoms: Purple Ear Drum and Hearing Loss : The Hearing Journal

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Clinical Consultation

Symptoms: Purple Ear Drum and Hearing Loss

Tawk, Karen; Abouzari, Mehdi; Djalilian, Hamid

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The Hearing Journal 76(01):p 17,18,19,20, January 2023. | DOI: 10.1097/01.HJ.0000911320.61498.5e
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A40-year-old patient presented to the clinic with a history of persistent aural fullness and exacerbating hearing loss on the right. He denied tinnitus, otalgia, headaches, vertigo, facial nerve symptoms, or trauma. His medical history is significant for surgery and radiation for olfactory neuroblastoma (tumor of the anterior skull base above the nose) and a sphenoid mucocele that was endoscopically excised one month before presentation. Physical examination demonstrated bulging of the tympanic membrane and a purple-colored tympanic membrane (Figure 1). The left ear was normal. The audiogram demonstrated a mixed moderately severe to severe hearing loss on the right with a 20-30 dB air-bone gap and mild sensorineural hearing loss on the left (Figure 2).

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Figure 1:
Image of patient’s ear. Arrows point to the tympanic membrane. Clinical Consultation, purple ear drum, middle ear cholesterol granuloma.
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Figure 2:
Patient’s audiogram. Clinical Consultation, purple ear drum, middle ear cholesterol granuloma.
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Figure 3:
Axial (horizontal) T1 fat saturated without (A) and with (B) gadolinium MRI showing hyperintensity (brighter than brain) in the middle ear, mastoid, and Eustachian tube. Clinical Consultation, purple ear drum, middle ear cholesterol granuloma.
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Figure 4:
Coronal (parallel to the face) T2 MRI showing middle ear fluid is slightly hyperintense (brighter) compared with the brain. Clinical Consultation, purple ear drum, middle ear cholesterol granuloma.
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Figure 5:
Axial (horizontal) CT of temporal bones showing bulging of the tympanic membrane. Clinical Consultation, purple ear drum, middle ear cholesterol granuloma.
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Figure 6:
Axial (horizontal) T2 MRI from 14 years prior showing fluid in Eustachian tube but middle ear with no fluid or cholesterol granuloma. Clinical Consultation, purple ear drum, middle ear cholesterol granuloma.

DIAGNOSIS: MIDDLE EAR CHOLESTEROL GRANULOMA

Our patient presented with a purplish-red mass bulging from the tympanic membrane. At first, this lesion is suspected to be a hypervascular mass. Vascular masses in the middle ear are uncommon and usually asymptomatic; however, patients may present with nonspecific symptoms such as pulsatile tinnitus, aural fullness, otalgia, and hearing loss. It is important to make the diagnosis before any middle ear surgery to avoid significant blood loss. The differential diagnosis can range from a dehiscent jugular bulb, aberrant internal carotid artery, and glomus tympanicum, to cholesterol granuloma and hemorrhage.

A dehiscent high-riding jugular bulb is the most commonly encountered cause for a blue/light purple mass under the tympanic membrane usually in the posterior inferior aspect of the middle ear. It would be unusual for it to be present behind the entire tympanic membrane. The internal jugular vein constitutes the continuum of the dural venous sinuses in the neck and lies below the hypotympanum. However, in rare instances, the bony jugular fossa can be absent, and a jugular bulb may extend above the level of the inferior tympanic annulus and show an indentation in the middle ear. It’s usually asymptomatic. When symptomatic, a high-riding jugular bulb may cause pulsatile tinnitus, conductive hearing loss, and vertigo. Conductive hearing loss can be due to the mass loading of the tympanic membrane, the ossicles, or blockage of the round window. A high-resolution computed tomography (CT) scan usually demonstrates dehiscence of the right bony septum since the dural sinuses and jugular vein are larger on the right. 1 Surgical repair can be performed to improve the conductive hearing loss.

Another possible cause of a purplish-red mass behind the tympanic membrane is an aberrant internal carotid artery (ICA). It’s a rare vascular anomaly to be seen in the middle ear (< 1%). The dehiscence of the cervical part of the ICA can be due to an error in embryogenesis (absence of the carotid canal and lateral posterior displacement of the carotid due to the persistence of embryonic vasculature) or acquired factors such as malignancies or skull base surgeries. Based on otoscopic findings and non-specific clinical presentation, an aberrant ICA often will be present in the anterior middle ear (where the carotid artery is located) and can appear purple, white, or red depending on the prominence and dominance of the overlying vasa vasorum (small blood vessels that feed the wall of the carotid artery). When present low in the middle ear, it can mimic a glomus tympanicum – a highly vascular benign tumor of the middle ear. However, a CT scan of the temporal bone helps avoid misdiagnosis, since, in the case of a glomus tumor, the size and aspect of the carotid canal are normal. 2 In addition, glomus tympanicum usually develops later in life, around the fifth to sixth decades and present with pulsatile tinnitus and conductive hearing loss.

Another consideration for a purple tympanic membrane is hemorrhage in the middle ear that can be due to direct trauma (e.g., temporal bone fracture) or barotrauma. Barotrauma can occur from aggressive attempts at ear popping with severe Eustachian tube dysfunction, barotrauma following a flight. The patient’s history can usually give the clinician the information needed to understand the etiology. Usually, barotrauma will present with bleeding just anterior to the malleus but can include the entire middle ear.

Cholesterol granulomas are cystic lesions commonly involving the petrous apex. Rarely, they can present behind the tympanic membrane as a purple or blue mass. First described by Paparella and Lim 3, two theories attempted to explain the development of cholesterol granuloma. The obstruction-vacuum theory states that the negative pressure due to Eustachian tube dysfunction or pneumatized air cells causes the extravasation of intravascular fluid which leads to chronic mucosal edema and breakdown and subsequent repeated episodes of bleeding. The hemorrhage incites an inflammatory reaction and the formation of cysts surrounding degrading blood products (cholesterol). The cysts gradually expand following a repeat of the described cycle. On the other hand, the exposed marrow hypothesis (primarily discussed for petrous apex cholesterol granuloma) states that the pneumatization of the bone expose the bone marrow to the hyperplastic mucosa. The coaptation of the bone marrow and mucosa will bleed, which will result in the inflammatory reaction and the formation of cysts. 4 Symptoms associated with cholesterol granuloma include hearing loss, tinnitus, aural fullness, headaches, and vestibular symptoms depending on how they expand and what structures are involved. Cholesterol granuloma can be identified by its high signal intensity (brighter than the brain) on FLAIR, T1-, and T2-weighted magnetic resonance imaging (MRI). On CT scan, middle ear cholesterol granulomas tend to not be as aggressive in growth and destruction compared with the petrous apex cholesterol granulomas that can be more aggressive.

In order to differentiate the aforementioned lesions, an MRI and CT scan of the temporal bone should be obtained. The patient’s MRI showed hyperintense (brighter than the brain) fluid in the right middle ear on T1 and T2-weighted images of the temporal bones (Figures 345). The temporal bone CT showed fluid in the right middle ear and mastoid (gray color) and bulging of the tympanic membrane without bony destruction. The absence of bony erosion indicates that a tumor is less likely to be present (Figure 6). These findings indicate that the bulging mass is a cholesterol granuloma. Based on the history of our patient, it is most probably due to Eustachian tube dysfunction caused by his previous surgery and radiation for his olfactory neuroblastoma.

Cholesterol granuloma can be managed by surgical drainage to prevent further expansion. When the cyst is symptomatic and located in the petrous apex, the treatment is challenging due to its proximity or erosion of critical structures (cochlea, carotid artery, and jugular vein). Its surgical drainage can be accomplished via infracochlear, transmastoid, middle fossa, transarcuate, or retrolabyrinthine approach. Resection is generally not attempted as drainage of the cholesterol granuloma suffices to stop its growth. 5 On the other hand, in case of a middle ear cholesterol granuloma, myringotomy and tube placement in the office treats the problem. The patient underwent a myringotomy in the posterior inferior quadrant and tube placement in the office. Brown (motor oil-like) fluid was aspirated from the middle ear; thus relieving the aural pressure and normalizing the tympanic membrane.

BONUS ONLINE 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 (horizontal) T1 fat saturated MRI showing the hyperintensity in the middle ear and Eustachian tube.

Video 2. Coronal (parallel to the face) T2 MRI showing the fluid consistency on T2 images and the mucocele in sinus.

Video 3. Axial (horizontal) T1 fat saturated post-gadolinium MRI showing the subtle inflammatory reaction around the cholesterol granuloma.

Video 4. Axial (horizontal) CT of temporal bones showing no destruction of the mastoid.

Video 5. Coronal (parallel to the face) CT of temporal bones showing no ossicular destruction.

Video 6. Axial (horizontal) T2 MRI from 2008 showing no cholesterol granuloma is present.

Watch the patient videos online at thehearingjournal.com.

REFERENCES

1. Shaikh MF, Mahboubi H, German M, Djalilian HR 2013 A novel approach for surgical repair of dehiscent high jugular bulb Laryngoscope 123 1803 1805 https://doi.org/10.1002/lary.23891
2. Honkura Y, Hidaka H, Ohta J, Gorai S, Katori Y, Kobayashi T 2014 Surgical treatment for the aberrant internal carotid artery in the middle ear with pulsatile tinnitus Auris Nasus Larynx 41 215 218 https://doi.org/10.1016/j.anl.2013.10.002
3. Paparella MM, Lim DJ 1967 Pathogenesis and pathology of the "idiopathic" blue ear drum Archives of Otolaryngology 85 249 258 https://doi.org/10.1001/archotol.1967.00760040251004
4. Jackler RK, Cho M 2003 A new theory to explain the genesis of petrous apex cholesterol granuloma Otology & Neurotology 24 96 106 https://doi.org/10.1097/00129492-200301000-00020
5. Lee A, Hamidi S, Djalilian H 2009 Anatomy of the transarcuate approach to the petrous apex Otolaryngology--Head and Neck Surgery 140 880 883 https://doi.org/10.1016/j.otohns.2009.01.001
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