LAUSR

INTRODUCTION Extra-axial cavernoma (EAC) at the cerebellopontine angle (CPA) is a rare clinical entity that can mimic radiologically several lesions encountered at this location. We report a case of extra-axial cavernoma at the cerebellopontine angle (EAC-CPA) and present a review of the literature. METHODS A Pubmed research was conducted looking for EAC-CPA lesions described in literature. After reviewing all the relevant articles, the following data were extracted and organized into a single table; patients' symptoms, radiological characteristics, surgical procedure, histopathology and outcome. RESULTS 18 cases (including ours) were identified from these reports. Mean age at diagnosis was 42 with a Male: Female ratio (2.6:1). The most commonly involved cranial nerves were the vestibulocochlear complex followed by the trigeminal nerve. The lesions were iso to hypodense on CT. On MR imaging the EAC-CPA can be solid or cystic. All lesions were approached using retrosigmoid craniotomies. Histologically, both intra and extra-axial cavernomas are identical, consisting of devoid vascular sinusoids with endothelial lining. The outcome was favorable in 16/18 of the described cases. One case presented a worsened facial paresis and one patient died due to excessive intra-operative bleeding and subsequent complications. CONCLUSION Despite the fact that EAC-CPA are rarely encountered, it should be kept in mind in the list of differential diagnosis, preparing both the surgeon and anaesthesiologist for the surgery of a vascular lesion. Specific radiological features, especially an associated developmental venous anomaly (DVA) could point to the diagnosis.