A case of recurrent subependymoma with subependymal seeding: case report.

Subependymoma is a rare, slow growing, rarely recurrent tumor. We report a case of re current subependymoma with subependymal seeding. An intraventricular tumor in the left temporal horn was detected in a 48-year-old female who presented with a 4-year history of dizziness and memory disturbance. Following near total surgical resection, a tumor diagnosis of subependymoma was confirmed by scattered clusters of isomorphic nuclei embedded in a dense fibrillary matrix of glial cell processes. Twenty-six months after surgery, follow-up (F/U) magnetic resonance (MR) imaging revealed tumor recurrence in the previous site which necessitated linear accelerator radiosurgery (LINAC). A further 21 months later, F/U MR imaging showed recurrent, multiple, enhanced, nodular lesions in the enlarged left lateral ventricle for which the patient underwent reoperation. Radiological and operative findings revealed local relapse with subependymal seeding. The pathological finding was similar to that of the previous tumor and compatible with subependymoma. The patient underwent radiation therapy for the residual tumor. This case history suggests that symptomatic residual tumors require close observation even though the clinical course of subependymoma is usually benign.