CAVERNOUS MALFORMATION PRESENTING AS AN EXTRAAXIAL CEREBELLOPONTINE ANGLE MASS - CASE-REPORT

OBJECTIVE AND IMPORTANCE: We describe a rare case of an extra-axial ca vernoma of the cerebellopontine angle without internal auditory canal involvement and with an unusual appearance on preoperative magnetic re sonance imaging (MRI). Only three cases of cerebellopontine angle cave rnomas have been previously reported, and none of these reports includ ed preoperative MRI. CLINICAL PRESENTATION: A young man presented with subacute left facial hypesthesia and chronic asymmetrical sensorineur al hearing loss. MRI revealed a mass, which was isointense on T1- and T2-weighted images, with evidence of hemorrhage (methemoglobin and hem osiderin). The lesion did not enhance after the injection of gadoliniu m. INTERVENTION: The lesion was removed without difficulty by a subocc ipital approach, with intraoperative electrophysiological monitoring o f facial and cochlear nerves. Facial paresis cleared postoperatively. CONCLUSION: The present case suggests that the appearance of cerebello pontine angle cavernomas as revealed by MRI may be similar to that of intraparenchymal cavernomas. This is in contrast to previously reporte d cases of extra-axial cavernomas at other sites. Evidence of hemorrha ge in an extra-axial lesion revealed by MRI suggests a possible diagno sis of cavernoma.