Interesting ImagesBrain PET Imaging of 11C-Methionine, 18F-FDG, and 18F-THK5351 in a Case of Lymphomatoid GranulomatosisHigashihara, Mana MD, PhD∗; Ishibashi, Kenji MD, PhD∗,†; Tokumaru, Aya M. MD, PhD‡; Ishii, Kenji MD∗,†; Iwata, Atsushi MD, PhD∗ Author Information From the ∗Department of Neurology, Tokyo Metropolitan Geriatric Hospital †Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology ‡Department of Diagnostic Radiology, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan. Received for publication April 3, 2022; revision accepted July 31, 2022. Conflicts of interest and sources of funding: The authors declare that they have no conflicts of interest. This study was supported by Grant-in-Aid for Scientific Research (C) No. 19 K08191 from the Japan Society for the Promotion of Science (to K. Ishibashi) and Award 2020 of Tokyo Metropolitan Geriatric Hospital (to M.H.). Authors’ contributions: M.H. and K. Ishibashi designed the study and drafted the manuscript. M.H., K. Ishibashi, A.M.T., K. Ishii, and A.I. obtained and interpreted the data. K. Ishibashi carried out the image processing. All authors read and approved the final manuscript. M.H. and K.Ishibashi contributed equally to this work. Correspondence to: Kenji Ishibashi, MD, PhD, Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan. E-mail: [email protected]pet.tmig.or.jp. Clinical Nuclear Medicine: December 2022 - Volume 47 - Issue 12 - p e749-e751 doi: 10.1097/RLU.0000000000004388 Buy Metrics Abstract A 52-year-old woman complained of upper respiratory symptoms and subsequently developed Wallenberg syndrome. Chest CT and brain MRI revealed multiple nodular lesions in the lungs and brain. She was pathologically diagnosed with low-grade lymphomatoid granulomatosis by lung biopsy. Brain PET examinations using 11C-methionine, 18F-FDG, and 18F-THK5351 were performed. Uptake of 11C-methionine and 18F-FDG was slightly increased in some lesions, likely reflecting the degree of inflammatory cell infiltration. 18F-THK5351 uptake was significantly increased in all lesions, likely reflecting the degree of reactive astrogliosis. This case illustrates the utility of PET studies for diagnosing lymphomatoid granulomatosis and provides insight into its pathophysiology. Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.