Intrinsic brainstem epidermoid cyst in childhood

Background: Epidermoid cysts are slow-growing, rare congenital lesions. They are most seen in the cerebellopontine angle, fourth ventricle, or parasellar regions. Patients typically become symptomatic between 20- and 40 years of age. We present a rare case of a symptomatic intrinsic brainstem epidermoid cyst in a 12-year-old girl with atypical radiological features. Case Description: A 12-year-old girl presented with progressive gait disturbances, disequilibrium, diplopia due to right-sided abducens paresis, left-sided facial paresis (HB grade II), headaches, nausea, and vomiting over the past 6 months. Magnetic resonance imaging (MRI) revealed an intrinsic lesion of the brainstem not present on MRI 4 years prior. A microsurgical gross total resection, including resection of cyst wall, was performed. The pathology report diagnosed the lesion as an epidermoid cyst. The patient improved significantly after resection. Conclusion: This pathology represents <1% of all intracranial tumors, and with only 21 documented pediatric intrinsic brainstem cases in medical literature, very rarely has an intrinsic brainstem location. We detail the medical history, work-up, surgical management, and postoperative outcomes, contributing to the limited body of knowledge regarding this exceptional entity.