Disappearance of "Elongated Pony Tail Sign" Following Chemoradiotherapy in a Case of Primary Cerebellopontine Angle Ependymoma With Spinal Drop Metastasis: 18 F-FDG PET/CT Scan Findings.

ABSTRACT

ABSTRACT Ependymomas are rare glial tumors that commonly arise from the lining cells of ventricular system and constitute ~10% of intracranial pediatric malignancies. The incidence of ependymoma in adults is rare. Due to close approximation with the ventricular system, subtentorial ependymomas are more prone to show cerebrospinal fluid metastasis compared with supratentorial ependymomas. We present a case of subtentorial cerebellopontine angle ependymoma with diffuse spinal drop metastases showing "elongated pony tail appearance" in a 69-year-old man with complete metabolic response on 18 F-FDG PET/CT imaging following chemoradiotherapy.