Differentiating Cholesterol Granuloma from Glomus Tumor: A Clinical Challenge

Received May 24, 2014 Accepted August 6, 2014 Address for correspondence Tae Hyun Yoon, MD, PhD Department of OtorhinolaryngologyHead and Neck Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea Tel +82-2-3010-3713 Fax +82-2-489-2773 E-mail thyoon@amc.seoul.kr Cholesterol granuloma is a histopathologic term used to describe the giant cell reaction to cholesterol deposits that occurs in sequestered, fluid-filled air cells that are normally pneumatized compartments of the temporal bone. It is a benign lesion which is known to be found in the middle ear cavity, mastoid air cells and petrous apex. Although cholesterol granuloma is a pathologic term describing a tissue response to cholesterol crystals, it is now recognized as a clinical disease entity especially in cases of unilateral blue eardrum without tympanic membrane perforation. Three factors are considered to play an important role in the development of cholesterol granulomas: obstruction of ventilation, microhemorrhage, and impaired drainage. Cholesterol granulomas are often found as pathologic lesions like granulation tissue in the middle ear and mastoid cavities during middle ear surgeries in patients with chronic otitis media or cholesteatoma. Cholesterol granulomas of the middle ear typically present as conductive hearing loss and a blue eardrum, whereas those at the petrous apex are incidentally identified or manifest as bony erosion with sensorineural hearing loss, tinnitus, vertigo, or cranial nerve impairment. Cholesterol granulomas in middle ear cavity and mastoid air cells are related with Eustachian tube dysfunction, so initial treatment of cholesterol granuloma is the insertion of ventilation tube in many cases. However, it is often necessary for the complete cure to do excision of the lesion through tympanomastoidectomy surgery. Korean J Otorhinolaryngol-Head Neck Surg 2014;57(12):809-14

Symptom: Serous Middle Ear Effusion and Hearing Loss

Symptoms: Purple Ear Drum and Hearing Loss

Cholesterol granulomas of the temporal bone can occur in the petrous apex, middle ear, and mastoid cavity. Although cholesterol granulomas in the petrous apex often extend to the middle cranial fossa, cholesterol granulomas in the middle ear and mastoids rarely invade the cranial cavity with bony erosion. We report a case of a large cholesterol granuloma involving the posterior cranial fossa with pneumatic mastoid and not affecting the middle ear. The patient had no otologic or neurologic symptoms, and the mass was found incidentally on a brain MRI included in a regular medical checkup. The mass was removed via a combined transmastoid and suboccipital approach without complications, and characteristic pathology findings demonstrated a cholesterol granuloma.

Symptoms: Middle Ear Mass and Hearing Loss

Patient: Male, 65-year-oldFinal Diagnosis: Tympano-mastoid cholesterol granulomaSymptoms: Hearing impairmentMedication:—Clinical Procedure: Endoscopic surgery of the earSpecialty: OtolaryngologyObjective:Unusual or unexpected effect of treatmentBackground:Cholesterol granuloma is a histological entity containing cholesterol crystals surrounded by foreign-body giant cells and chronic inflammation. Tympanic cholesterol granuloma is a rare disease, while petrous bone cholesterol granuloma is more common. Surgery consists of elective management in most cases of CGs. There are several types of surgery described to treat cholesterol granuloma; however, a case treated by primary endoscopic ear surgery has not yet been described.The aim of this case report is to present the endoscopic characteristics of cholesterol granulomas and show how endoscopic ear surgery is possible in isolated and selected cases with this pathology.Case Report:We report the case of a 65-year-old patient affected by a cholesterol granuloma of the middle ear, with progressive hearing impairment and fullness of the left ear. The granuloma was diagnosed via medical imaging using magnetic resonance imaging, which identified the typical high signal intensity in T1- and T2-weighted images. In this case, cholesterol granuloma was limited to the epitympanic and mesotympanic regions. For small cholesterol granulomas confined to the middle ear, a canal wall-up or wall-down tympanoplasty plus ventilation tube insertion are usually performed. In this case, primary endoscopic surgery was performed under general anaesthesia to remove the presumed cholesterol granuloma. It was completely removed by this approach, without facial nerve injuries or postoperative complications. The patient had no disease recurrence at clinical and radiological investigation at 1-year follow-up.Conclusions:An exclusive endoscopic approach to remove cholesterol granuloma is feasible. However, it should only be performed in selected cases.

Imaging cholesteatoma

Double‐barrel stenting in infracochlear approach for drainage of petroux apex cholesterol granulomas

There is ongoing debate on the pathogenic mechanisms of cholesterol granuloma formation in the temporal bone. The purpose of this report is to provide evidence in support of the exposed marrow hypothesis in explaining the pathogenesis of petrous apex cholesterol granuloma. Retrospective single case study. The primary outcome evaluated was the diagnosis of a new cholesterol granuloma in a petrous apex that previously demonstrated radiologic evidence of bone marrow exposed to petrous apex air cells. A patient with a unilateral petrous apex cholesterol granuloma develops a new, contralateral cholesterol granuloma in a hyperpneumatized temporal bone petrous apex shown previously to have medullary bone exposed to air cells. This report implicates the medullary-air cell interface in a hyperaerated temporal bone petrous apex in the development and growth of a petrous apex cholesterol granuloma.

Cholesterol granulomas are benign granulomatous lesions caused by tissue reaction to a foreign body such as cholesterol crystals. These crystals have been are associated with pathological conditions of pneumatized spaces, including those causing inadequate aeration, obstruction of drainage, and hemorrhage in pneumatized spaces, and where materials trapping materials, such as hemosiderin or cholesterol become trapped, and then forming a cholesterol granuloma. Cholesterol granulomas are frequently found in the temporal bones, with the middle ear, mastoid caverna, and petrous apex being the most commonly affected sites. As there have been few reported cases of cholesterol granulomas presenting as a mass in the external acoustic canal (EAC), a cholesterol granuloma occluding the entire EAC in a pediatric patient is considered quite rare. We encountered a large cholesterol granuloma occupying the entire EAC, resulting in total EAC occlusion in a 12-year-old girl. The granuloma was diagnosed via medical imaging and surgically excised.

Cholesterol granulomas (CGs) are the most common benign lesions of the petrous apex (PA) and have distinct computed tomography (CT) and magnetic resonance imaging (MRI) characteristics. On CT, CGs of the PA (PACG) present as expansile lesions with erosion of bony trabeculae. MRI shows a hyperintense lesion on T1-and T2-weighted images and do not enhance with gadolinium. The objective is to describe the radiographic features of CGs of the skull base that do not arise from the PA. This study is a retrospective review. Three patients were operated on for suspected recurrent endolymphatic sac tumor, intracranial cholesteatoma, and recurrent sphenoid wing meningioma based on CT and MRI findings. Pathology results were consistent with CG in all three cases. All patients had bone erosion on CT. These skull base CGs did not demonstrate similar MRI features. These lesions were hyperintense, iso-to-hyperintense, and hypointense on T1-weighted MRI, respectively. These CGs were hyperintense in two cases and iso-to-hyperintense in one case on T2-weighted MRI. These lesions either demonstrated central or rim enhancement after gadolinium administration. Skull base CGs that do not arise from the PA demonstrate a broad spectrum of radiographic characteristics on MRI that are not typical of PACG.

Surface Matching based on External and Internal Anatomy of the Temporal Bone Applicable for Lateral Skull Base Surgery

Rationale:A cholesterol granuloma (CG) is usually found in the middle ear, papilla, orbits, petrous apex, and choroid plexus, but is highly uncommon in the skull. In spite of benign clinicopathological lesions, bone erosion can be seen occasionally in the patient with CG. The optimal treatment strategy is radical surgery, but complete excision is usually impossible due to anatomical restrictions and a risk of injury to the key structures located nearby. Here, we report a patient with CGs in the suprasellar and sellar regions who was successfully treated with Java brucea and Chinese herbal medicine.Patient concerns:A 31-year-old man presenting with progressive decreased vision in both eyes was analyzed.Diagnoses:A skull magnetic resonance imaging (MRI) scan showed a low-density tumor in the uprasellar and sellar regions and histopathological examination revealed a CG.Interventions:The patient was referred the surgery and radiotherapy. In the meantime, brucea soft capsules and herbal medicine combined were administered to him.Outcomes:The related clinical symptoms and signs resolved significantly after several months, as his therapy progressed. The patient showed no sign of recurrence during the treatment period. Furthermore, he was still alive and disease-free at 37 months of follow-up visit.Lessons:Overall, brucea soft capsules and a Chinese herbal formula treatment combined could be beneficial in improving the patient's quality of life with CG in the skull.

BackgroundCholesterol granuloma (CG) may involve the middle ear, the mastoid bone and the petrous apex. However, CG presenting as a mass obstructing the external ear canal (EEC) is relatively rare and it can be a diagnostic challenge.Case PresentationWe report a case of a CG occupying the mastoid antrum and presenting as a mass into the EEC. Temporal bone computerized tomography showed a soft tissue mass which eroded the posterior-superior bony wall of the EEC. On magnetic resonance imaging, the mass revealed a high signal on both T1 and T2-weighted images. The CG was removed by a mastoidectomy procedure and the histopathologic report confirmed the diagnosis of CG. A type III tympanoplasty was performed.ConclusionsThe postoperative course was uneventful.

Bilateral middle ear cholesterol granuloma in familial hypercholesterolemia