Cholesterol granuloma, or cholesterol cyst, is a benign mass that contains brownish-yellow debris with cholesterol crystals and is characterized by slow growth. These lesions can be found in any part of the body, but they frequently arise throughout the temporal bone of the skull, with the petrous apex of the inner ear being the most common site.
Symptoms
Patients suffering from cholesterol granuloma present with varying symptoms including hearing loss, vertigo, headache, tinnitus, facial spasms, and double vision. The presence of cholesterol granuloma is often unknown until these symptoms are investigated further. The condition typically affects young to middle-aged patients often with a history of chronic otitis media, an infection of the middle ear.
Diagnosis
Cholesterol granuloma is usually diagnosed by a CT or MRI scan. Further pathological examination is carried out after surgery. Granulomas are composed of brownish-yellow fluid that contains cholesterol crystals, multi-nucleated giant cells, red blood cells and blood breakdown products. The lesion is usually surrounded by fibrous connective tissue and fragile blood vessels that are prone to rupture.
Prognosis
If left untreated, cholesterol granulomas of the middle ear will lead to a host of problems. These include damage to the delicate structures of the ear, possibly leading to hearing loss and problems with balance; damage to the facial nerve, which can cause paralysis; and possible spread of infection to the brain. Unfortunately, cholesterol granuloma has high recurrence rates.
Treatment
Treatment of cholesterol granuloma involves drainage and ventilation of the cyst. However, if the granuloma is particularly large and destructive, complete removal may be necessary. There are a number of possible surgical approaches, which are dependent on the size of the cyst, the skills of the surgeon, and the status of the patients hearing. The Endoscopic Endonasal Approach (EEA) is a minimally invasive procedure that uses the nose as a corridor to reach and remove the cyst. Using the nose means there are no incisions in the face or head and the technique is used to preserve hearing. If the patient has already suffered severe hearing loss, the cyst is normally located using an incision behind the ear.
