A 48-year-old woman comes to the office due to an intermittent ear discharge over the last 2 years. She has also noticed decreased hearing in the right ear recently. Past medical history is significant for obesity, hyperlipidemia, seasonal allergies, and diet-controlled diabetes mellitus. Otoscopy shows a small perforation in the right tympanic membrane and a pearly mass behind the membrane. Conduction hearing loss is noted in the right ear. The remainder of the ear, nose, and throat examination is normal. Which of the following is the most likely cause of this patient's aural mass?
Cholesteatomas are collections of squamous cell debris that form a round, pearly mass behind the tympanic membrane in the middle ear. They can occur congenitally or may develop in adults as either an acquired primary lesion or secondary to infection, trauma, or surgery of the middle ear. Primary cholesteatomas are a result of chronic negative pressure in the middle ear causing retraction pockets in the tympanic membrane that become cystic; as the squamous cell debris accumulates, a cholesteatoma is formed. Secondary cholesteatomas occur after squamous epithelium migrates to or is implanted in the middle ear ("skin in the wrong place").
Cholesteatomas most commonly cause painless otorrhea. They also can produce lytic enzymes and are often discovered when they erode through the auditory ossicles, causing conductive hearing loss. If a mass grows sufficiently large, it can erode into the vestibular apparatus or facial nerve, causing vertigo or facial palsies.
(Choice A) Cholesterol granulomas can form in the middle ear after hemorrhage but are much less common than cholesteatomas. They appear as bluish-black gelatinous material behind the tympanic membrane. Despite what the name implies, cholesteatomas do not contain any lipid or cholesterol components.
(Choice B) A facial nerve neuroma can grow in the middle ear as the facial nerve courses through this territory. However, it would present with unilateral facial paralysis.
(Choice C) Squamous cell carcinoma is the most common malignant tumor of the ear canal. It typically appears as an ulcerated plaque or nodule. The most common symptom is local or regional pain.
(Choice D) Granulomatous disease of the ear can occur but is uncommon and usually develops in conjunction with a systemic disease, such as sarcoidosis, granulomatosis with polyangiitis, or Langerhans cell histiocytosis.
Educational objective:
Cholesteatomas are collections of squamous cell debris that form a mass behind the tympanic membrane. Cholesteatomas can be congenital or may occur as an acquired primary lesion or following infection, trauma, or surgery of the middle ear. They can cause hearing loss due to erosion into auditory ossicles.