Giant cholesterol granuloma of petrous apex

Abstract

Cholesterol granulomas are chronic inflammatory lesions located primarily in the apex of the petrous part of the temporal bone. They are benign, tumor-like lesions, consisting of a cystic cavity filled with a chocolate-brown fluid and present as hyperintense masses on T1 and T2 sequences on MRI. The most common causes of cholesterol granulomas are chronic middle ear infections and traumas, explaining their prevalence in young to middle aged patients. Due to their progressively expanding nature, clinical presentation include vertigo, diplopia, tinnitus, hearing loss and seizures. Treatment of cholesterol granulomas consists of two different approaches: watch and wait or radical surgery to remove the granulomatous tissue. We present the case of a 38-year-old male patient who was admitted to the Neurology Clinic with complaints of loss of consciousness, headache, pain on the left side of the face and tinnitus in the left ear. These symptoms had been present for some time and gradually worsened in intensity and frequency. Initially after an EEG was performed, the patient showed signs of focal epilepsy and began treatment accordingly. Subsequently, a CT and an MRI of the head and neck were performed, which showed a large, well demarcated expansile mass within the left petrous apex, which was hyperintense on T1 and T2. Based on his clinical presentation and radiologic findings, a diagnosis of cholesterol granuloma was established. Through this case report we hope to emphasize the role imaging modalities play in the diagnosis and appropriate management of cholesterol granulomas.

Radiological Classification and Management Algorithm of Petrous Apex Cholesterol Granuloma

“…Facial spasms result from the irritation of the facial nerve inside the IAC, at the level of the cerebellopontine angle, or inside the fallopian canal. Sensorineural hearing loss, tinnitus and dizziness originate from compression of the eighth nerve or from the erosion of the otic capsule [4,9].…”

“…Late signs and symptoms are middle ear effusion, which appears when the eustachian tube is eroded by the granuloma, speech and swallowing problems and seizures, which are very rare [9].…”

“…Patients may remain asymptomatic for long periods of time and the outbreak of symptoms is related to the expansion of the cyst. The most common symptom is hearing loss, which affects almost 50% of the patients, followed by headache, dizziness, facial palsy, facial pain or spasms and diplopia [4,[7][8][9].…”

Testicular cholesterol granuloma mimicking a testicular tumor: A case report

“…The pathophysiology of ChG development remains unknown and the suggested cause of development may differ depending on the location. Hemorrhage, drainage obstruction and the disruption of ventilation are factors that may be associated with the development of the condition (8). Trauma leading to inflammation and ischemia results in the extravasation of blood containing cholesterol, fibrin and hemosiderin.…”

Xanthogranuloma of the suprasellar region mimicking cystic craniopharyngioma: A case report

“…[ 3 , 7 ] Xanthogranuloma can occur in any part of the body, but the most common site of occurrence is in the petrous apex of the anterior skull base. [ 1 , 8 ] Sellar xanthogranuloma is an extremely rare entity with an incident rate of 0.7% among 1367 positive sellar/parasellar MRI findings. [ 2 ] It was first described by Shirataki et al .…”