終糸脂肪腫

Filum Lipoma

Point

・脊髄終糸の脂肪腫（異所性脂肪組織）はMRI上しばしば認められるが，多くは無症候で低位脊髄円錐を呈さず，病的意義はない．

・症候性例が手術適応であることに異論はなく，無症候で低位脊髄円錐を示す例への予防的手術の適応は意見が分かれている．

・手術リスクは比較的小さいが，神経生理学的手技のもと確実に行うことが大切である．

　Filum lipomas, a subtype of spinal lipomas, are ectopic fat tissue deposits of the filum terminale categorized as closed spinal dysraphism. They are occasionally and incidentally observed on MRI images, but generally require little surgical treatment. Early untethering surgery is recommended for symptomatic patients, whereas asymptomatic patients presenting normal level of the conus medullaris require no therapy and are regarded as having a normal variation. Prophylactic untethering surgery can be an option for asymptomatic patients with low set conus medullaris. Untethering surgery should be safely conducted using electrophysiological procedures. Herein, we summarize the clinical characteristics of the filum lipoma and describe our routine surgical procedures.