An isolated cavernous malformation of the sixth cranial nerve: A case report and review of literature

BACKGROUND: Isolated cavernous malformation (CM) of the abducens nerve has not been reported in the literature. Herein, the authors address the clinical importance of these lesions and review the reported cases of CM from 2014 to 2020. CASE DESCRIPTION: A 21-year-old man presented with binocular diplopia and headache from 2 months before his admission. The neurological examination revealed right-sided abducens nerve palsy. The brain MRI revealed an extra-axial pontomedullary lesion suggestive of a CM. The lesion was surgically removed. During the operation, the abducens nerve was resected considering the lesion could not be separated from the nerve and an anastomosis was performed using an interposition nerve graft and fibrin glue. Pathological examination of the resected lesion revealed that it was originated from within the nerve. The patient’s condition improved in postoperative follow-ups. CONCLUSION: Surgical resection of the cranial nerves CMs is appropriate when progressive neurological deficits are present. If the lesion is originated from within the nerve, we suggest resection of the involved nerve and performing anastomosis. Novel MRI sequences might help surgeons to be prepared for such cases and fibrin glue can serve as an appropriate tool to perform anastomosis when end-to-end sutures are impossible to perform.