Extra-axial cerebellopontine angle cavernoma: A case report and review of literature.

Background: Extra-axial cavernomas at the cerebellopontine angle (CPA) are rare clinical entity that can radiologically mimic several lesions encountered at this location.

Case Description: A 36-year-old female patient referred to our emergency service with acute decreased level of consciousness and vomiting. Neurological examination showed Glasgow Coma Scale of 12 with downbeat nystagmus of the right eye. Brain computed tomography scan and magnetic resonance imaging showed multilobulated extra-axial mass lesion located in the right CPA. The lesion was with various signal intensities in T1- and T2-weighted images suggestive of hemorrhages of different ages. T2 gradient echo sequences showed multiple sinusoid-like channels and diffuse hemosiderin deposition. These figures were compatible with cavernous malformation. The patient was operated by retrosigmoid approach. Dissection of the mass from the trigeminal, facial, vestibulocochlear, and lower cranial nerves was performed and total resection of the tumor was achieved. Histopathological examination confirmed the diagnosis of cavernoma.

Conclusion: Although CPA cavernomas are very rare, they should be considered for differential diagnosis when evaluating CPA lesions preoperatively for better intraoperative management and postoperative outcomes.