NITTA Masayuki
   Department   School of Medicine(Tokyo Women's Medical University Hospital), School of Medicine
   Position   Assistant Professor
Article types Case report
Language English
Peer review Peer reviewed
Title IgG4-related brain pseudotumor mimicking CNS lymphoma. A case report.
Journal Formal name：Neuropathology : official journal of the Japanese Society of Neuropathology
Abbreviation：Neuropathology
ISSN code：14401789/09196544
Domestic / ForeginForegin
Volume, Issue, Page 42(6),pp.526-533
Author and coauthor OSHIMA Rie†, IKEGUCHI Ryotaro, WAKO Syo, MIZUNO Takafumi, ABE Kayoko†, NITTA Masayuki, MURAGAKI Yoshihiro, KAWAMATA Takakazu, MASUI Kento, YAMAMOTO Tomoko, SHIBATA Noriyuki, SHIMIZU Yuko, KITAGAWA Kazuo
Publication date 2022/12
Summary Here, we report a case of IgG4-related brain pseudotumor (IgG4-BP) in a 39-year-old woman, mimicking central nervous system (CNS) lymphoma. She presented with headache, fever, and fatigue. Her medical history was notable for appearance of a tumefactive brain lesion seven years before. Brain biopsy performed at the age of 32 revealed nonspecific inflammatory changes, and her condition improved with oral low-dose steroid therapy. Magnetic resonance imaging performed at the age of 39 identified a hyperintensity lesion with edema located at the medial temporal lobe region adjacent to the inferior horn of the left lateral ventricle on fluid-attenuated inversion recovery images, which showed gadolinium-contrast enhancement on T1-weighted images and a slightly hyperintensity signal on diffusion-weighted images. Methionine-positron emission tomography (PET) depicted a high methionine uptake in the lesion. Additionally, soluble levels of interleukin (IL)-2 receptor (sIL-2R) and IL-10 were increased in cerebrospinal fluid (CSF). Based on these findings, we suspected CNS lymphoma and performed partial resection of the brain lesion. Pathological examination revealed prominent lymphocytic infiltration associated with plasma cell infiltration. Most of the plasma cells were immunoreactive for IgG4. Storiform fibrosis and partially obliterative phlebitis were concomitantly observed. Thus, the patient was diagnosed as having IgG4-BP. To the best of our knowledge, this is the first case report of IgG4-BP with detailed findings obtained by CSF testing, methionine-PET, and pathological examination. Because IgG4-related diseases can present as a pseudotumor that mimics CNS lymphoma, it is essential to carefully differentiate IgG4-BP from CNS lymphoma.
DOI 10.1111/neup.12839
PMID 36210695