Radiology Quiz Case 1

Diagnostic Dilemma: Cerebellopontine Angle Lipoma Versus Dermoid Cyst

“…Intracranial lipomas are benign lesions consisting of adipose tissue that originate from congenital malformations of the meninges [ 3 - 5 ]. The meninx primitiva is a precursor structure from which the arachnoid, pia, and dura mater are derived to form the mesenchymal covering of the brain.…”

“…Lipomas can occur anywhere within the intracranial compartment, although the CPA is a relatively rare location. Most intracranial lipomas tend to be midline, supratentorial, and involve the corpus callosum [ 5 , 9 - 10 ]. CPA lipomas comprise approximately 10% of intracranial lipomas, 0.14-0.15% of CPA tumors, and 0.1-0.5% of intracranial tumors overall [ 5 , 7 , 11 - 12 ].…”

“…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 ].…”

“…This is because CPA lipoma symptomatology resembles that of other CPA tumors, including vestibular schwannomas, meningiomas, and so on. Despite their rarity, CPA lipomas should be included in the differential diagnosis of patients with cochleovestibular signs (sensorineural hearing loss, tinnitus, and vertigo), facial nerve signs (hemifacial spasms and facial motor impairment), and trigeminal nerve signs (sensory loss and trigeminal neuralgia) [ 5 , 7 , 14 ]. The most common signs of CPA lipomas are hearing loss, tinnitus, vertigo, facial symptoms (facial and trigeminal nerve signs), and headaches [ 11 ].…”

“…The most common signs of CPA lipomas are hearing loss, tinnitus, vertigo, facial symptoms (facial and trigeminal nerve signs), and headaches [ 11 ]. Severe cases have been recorded wherein a CPA lipoma produced long tract signs, which included right arm tremor, weakness, and ataxia [ 5 ].…”