Lipomas of the Internal Auditory Canal and Cerebellopontine Angle

Abstract

Neuroimaging represents an extremely important tool for this diagnosis. Attempts to achieve complete resection may result in severe neurologic sequelae, especially in large lesions. Observation with repeated imaging in order to detect growth of the lesion is usually recommended. Debulking of the tumor, mainly aimed at brain stem and cranial nerve decompression, should be considered in cases of disabling and uncontrolled neurologic symptoms and signs.

Diagnostic Dilemma: Cerebellopontine Angle Lipoma Versus Dermoid Cyst

“…It is unknown if intracranial lipomas are more likely to occur in men or women [ 4 - 5 , 11 ]. Literature regarding sidedness for lipomas is also lacking [ 11 ].…”

“…Literature regarding sidedness for lipomas is also lacking [ 11 ]. Bacciu et al calculated from their sample size of eight patients that the mean age at diagnosis of internal auditory canal (IAC) CPA lipomas was 44.8 years and ranged from 31 to 74 years [ 4 ]. Lagman et al calculated that the mean age was 37.1 years, ranging from 0.6-77 years in which 117 patients with CPA lipomas were identified [ 11 ].…”

Lesions Mimicking Small Vestibular Schwannomas

“…We might have identified them to be hyperintense, if T1 thin slice images would have been available. Since both tumors in our series showed an uptake of contrast and were still visible in fat suppression, they were misdiagnosed as a VS. Bacciu et al 19 also reported on an uptake of contrast agent in four of eight lipomas of the CPA which led to the misdiagnosis of VS. The uptake of contrast agent and a persisting signal in fat suppression is not typical for lipomas (that typically solely consist of adipocytes), but it may be explained by the varied proportions of fat in relation to the surrounding nerve fibers in our lipochoristoma cases.…”

“…IAC lipochoristomas typically show an infiltration between nerve fibers, 12,15,19,20 which makes them more difficult and unfavorable to resect. 19,21,22 This effect was also noted during surgery in one of our two lipochoristomas, where a strong adherence of the tumor to the surrounding tissue was encountered. This may explain why both lipochoristoma cases showed functional results below the average compared with the meningioma or schwannoma cases.…”

Lipoma on the antitragus of the ear

“…on the ear, most are located in internal auditory canals, where approximately 150 cases have been reported in the literature worldwide [3]. Lipomas rarely originate from the external ear where only a few cases have been reported from the ear lobule [4], and a only three cases from the ear helix [1,6,7] Bassem et al reported a case of lipoma of the pinnal helix on the 82-year-old woman, which presented a single, 3x3x2cm-sized, pedunculated mass [1].…”