title: Primary central nervous system large B-cell lymphoma with prolific, mixed T-cell and macrophage infiltrates, mimicking multiple sclerosis.
abstract: Although tissue confirmation is essential for a diagnosis of primary central nervous system large B-cell lymphoma (PCNSBL), accurate assessment may still be difficult, even when tissue is obtained. We report a 59-year-old man, first diagnosed as multiple sclerosis by open biopsy at another institution, who was then correctly diagnosed as PCNSBL after stereotactic biopsy at our hospital. The initial biopsy showed heavy lymphoid and macrophage influx with visible demyelination. On rebiopsy, a diffuse infiltrate of small to medium-sized lymphocytes was prominent and largely stained as T cells (CD3) by immunohistochemistry. There was also an admixture of macrophages, but this time, relatively low numbers of large malignant cells were also identified. The latter stained as B cells (CD20), enabling a diagnosis of B-cell lymphoma, and the condition responded fully to high-dose methotrexate. It is thus possible for PCNSBL to be histologically misinterpreted as a result of ancillary inflammation, characterized here as a profusion of T cells and macrophages.
authors.affiliation: Department of Neurosurgery, Kitasato University School of Medicine, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555, Japan. utsuki@med.kitasato-u.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Utsuki
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Oka
authors.forename: Tomoko
authors.initials: T
authors.lastname: Miyazaki
authors.forename: Tomoya
authors.initials: T
authors.lastname: Yamazaki
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Yasui
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Fujii
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kawano
authors.forename: Wataru
authors.initials: W
authors.lastname: Tokuyama
authors.forename: Keiichi
authors.initials: K
authors.lastname: Iwabuchi
authors.forename: Isao
authors.initials: I
authors.lastname: Okayasu
authors.forename: Saburo
authors.initials: S
authors.lastname: Yagishita
mesh_terms: D018951:Antigens, CD20 / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis; D001706:Biopsy; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology*; D017252:CD3 Complex / Q000032:analysis; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D006801:Humans; D016393:Lymphoma, B-Cell / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology*; D008264:Macrophages / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008727:Methotrexate / Q000008:administration & dosage; D008875:Middle Aged; D009103:Multiple Sclerosis; D013238:Stereotaxic Techniques; D013601:T-Lymphocytes / Q000473:pathology*; D016896:Treatment Outcome
chemical_list: D018951:Antigens, CD20; D014408:Biomarkers, Tumor; D017252:CD3 Complex; D008727:Methotrexate