전연수조에 발생한 비전형적인 영상소견을 가지는 유표피종

Epidermoid cyst with atypical radiologic finding at premedullary cistern

Epidermoid cysts are benign tumors that account for 1% of all intracranial tumors. Radiologic findings are identical in signal of CSF. MR diffusion weighted image is useful for differentiation from arachnoid cysts. In our case, a 16-year-old male patient was admitted to our institute with severe occipital headache, nausea and vomiting for 5 days. CT findings revealed a lobulated homogenous mass that was high density in the right premedullary cistern. MRI findings were high signal on T1 weighted image and low signal on T2 weighted image without restriction on diffusion weighted image. Presumed diagnosis based on radiologic finding was uncertain mass with hemorrhage. We performed surgical removal with right far-lateral suboccipital approach. Whitish mass was found in capsule without hemorrhage. Histopathologic diagnosis was reported as epidermoid cyst. Postoperatively, his symptoms were completely relieved. The current case is the report of intracranial epidormoid cyst in atypical radiologic finding.