[A case of idiopathic cranial hypertrophic pachymeningitis presenting Tolosa-Hunt syndrome].

A 48-year-old female was seen because of left orbital pain. The neurological findings were normal at her first visit. She presented temporary double vision during conservative period. Plain CT revealed no mass around the sellar region. Enhanced CT revealed enhanced mass in the left cavernous sinus. MRI revealed low intensity lesion on both T1 and T2 weighted images. Enhanced MRI showed strongly enhanced mass extended from the left cavernous sinus to the dura of sellar floor, the contralateral cavernous sinus, and cerebellar tentorium. Angiography showed stenosis of the left internal cerebral artery. Biopsy from the dura of the tentorium was performed via anterior temporal approach. Abundant collagen fibers with hyalinization were seen in the thickened dura. A final diagnosis of idiopathic cranial hypertrophic pachymeningitis presenting Tolosa-Hunt syndrome was made. Symptoms were free just after the surgery, however, the regrowth of the tentorial lesion was found on MRI after one year. The size of the lesion decreased after administration of steroid.