Peripheral facial palsy, the only presentation of a primitive neuroectodermal tumor of the skull base

•A 2-month-old male infant presenting with only peripheral facial palsy was diagnosed with a primitive neuroectodermal tumor of the skull base.•Primitive neuroectodermal tumors located in the skull base are rarely detected in infants.•After subtotal resection of the tumor, asymmetrical facial expression showed mild improvement.

IntroductionPeripheral facial palsy is rarely caused by primary neoplasms, which are mostly constituted of tumors of the central nervous system, head and neck, and leukemia.Presentation of caseA 2-month-old male infant presented with asymmetric facial expression for 3 weeks. Physical examination revealed suspicious findings of right peripheral facial palsy. Computed tomography of the temporal bone revealed a suspicious bone tumor centered in the right petrous bone involving surrounding bones with extension into the middle ear cavity and inner ear. Subtotal resection of the tumor was performed due to crucial structures adjacent the mass. Histopathology and immunohistochemistry of the resected tumor was consistent with primitive neuroectodermal tumor.ConclusionWe report a rare case of a primitive neuroectodermal tumor located at the skull base presenting with only peripheral facial palsy.