title: Gadolinium enhancement patterns of tumefactive demyelinating lesions: correlations with brain biopsy findings and pathophysiology.
abstract: Tumefactive demyelinating lesions (TDLs) can mimic brain tumors on radiological images. TDLs are often referred to as tumefactive multiple sclerosis (TMS), but the heterogeneous nature and monophasic course of TDLs do not fulfill clinical and magnetic resonance imaging (MRI) criteria for multiple sclerosis. Redefining TDLs, TMS and other inflammatory brain lesions is essential for the accurate clinical diagnosis of extensive demyelinating brain lesions. We retrospectively analyzed MRI from nine TDL cases that underwent brain biopsy. Patterns of gadolinium enhancement on MRI were categorized as homogenous, inhomogeneous, patchy and diffuse, open ring or irregular rim, and were compared with pathological hallmarks including demyelination, central necrosis, macrophage infiltration, angiogenesis and perivascular lymphocytic cuffing. All cases had coexistence of demyelinating features and axonal loss. Open-ring and irregular rim patterns of gadolinium enhancement were associated with macrophage infiltrations and angiogenesis at the inflammatory border. An inhomogeneous pattern of gadolinium enhancement was associated with perivascular lymphocytic cuffing. Central necrosis was seen in cases of severe multiple sclerosis and hemorrhagic leukoencephalopathy. These results suggest that the radiological features of TDLs may be related to different pathological processes, and indicate that MRI may be useful in understanding their pathophysiology. Further investigation is needed to determine the precise disease entity of these inflammatory demyelinating brain lesions.
authors.affiliation: Department of Neurology, School of Medicine, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan, masaki.kob@nifty.ne.jp.
authors.forename: Masaki
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Yuko
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Shibata
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Uchiyama
mesh_terms: D000328:Adult; D000888:Antibodies, Anti-Idiotypic / Q000097:blood; D000974:Antibodies, Antinuclear / Q000097:blood; D051401:Aquaporin 4 / Q000276:immunology; D001706:Biopsy; D001921:Brain / Q000473:pathology*; D005260:Female; D005682:Gadolinium; D006801:Humans; D007091:Image Processing, Computer-Assisted; D004684:Leukoencephalitis, Acute Hemorrhagic / Q000097:blood / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000097:blood / Q000175:diagnosis*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: C496030:AQP4 protein, human; D000888:Antibodies, Anti-Idiotypic; D000974:Antibodies, Antinuclear; D051401:Aquaporin 4; D005682:Gadolinium