[Surgical seeding of an anaplastic ependymoma]

Ependymomas can relapse at the primary site and disseminate to the spinal cord. Furthermore, extraneural metastases are rare. We present a case of anaplastic ependymoma with extraneural metastasis, possibly caused by surgical seeding. An 18-year-old female was referred to us after experiencing frequent convulsive attacks. At age 9 years, she underwent partial resection of a left frontal anaplastic ependymoma, followed by 45 Gy radiation. At age 15 years, a recurrent tumor was totally removed. Three years later, magnetic resonance images revealed a left frontal recurrent tumor and a new parietal lesion. Our preoperative diagnosis of the parietal tumor was a radiation-induced meningioma. However, intraoperative pathological examinations revealed the lesion to be an anaplastic ependymoma. The tumor, which was located in the epidural space and had invaded extensively into the cranial bone, was gross totally removed. Although extremely rare, surgical seeding of anaplastic ependymomas should be considered as a differential diagnosis for recurrent tumors in the surgical field.