Interesting Images18F-FDG and 68Ga-FAPI-04 PET/CT Imaging of a Case With Immunoglobulin G4–Related Disease Presenting as Hepatic MassesZhang, Zeyu MM∗; Jiang, Hui MD†; Zhang, Lu MD∗; Cheng, Chao MD∗; Zuo, Changjing MD∗ Author Information From the Departments of ∗Nuclear Medicine †Pathology, Changhai Hospital, Navy Military Medical University, Shanghai, China. Received for publication May 17, 2022; revision accepted July 15, 2022. Conflicts of interest and sources of funding: The authors declare that they have no conflicts of interest. This work is supported by the “234 Discipline Climbing Plan” of the First Affiliated Hospital of Naval Medical University (grant no. 2019YPT002 and 2020YPT002). None declared to all authors. This study was approved by the Ethics Committee of the First Affiliated Hospital of Naval Medical University (Changhai Hospital, CHEC2021-071). Correspondence to: Changjing Zuo, MD, Department of Nuclear Medicine, Changhai Hospital, Navy Military Medical University, 168 Changhai Rd, Yang Pu District, Shanghai 200433, China. E-mail: [email protected]; and Chao Cheng, MD, Department of Nuclear Medicine, Changhai Hospital, Navy Military Medical University, 168 Changhai Rd, Yang Pu District, Shanghai 200433, China. E-mail: [email protected]. Clinical Nuclear Medicine: December 2022 - Volume 47 - Issue 12 - p 1092-1094 doi: 10.1097/RLU.0000000000004377 Buy Metrics Abstract Two hepatic masses were discovered through ultrasonography in a 50-year-old man with increased CA19-9, which is highly suspicious for malignancy. PET/CT images revealed intense 18F-FDG and 68Ga-FAPI-04 uptake in intrahepatic lesions. Histopathology with biopsy confirmed the diagnosis of immunoglobulin G4 (IgG4)–related disease. Here, we reported a case of IgG4-related primary localized pseudotumor without any other organ involvement. We concluded that in clinical work, if intrahepatic masses show high uptake of 18F-FDG or 68Ga-FAPI-04, intrahepatic IgG4-related disease should be considered for differential diagnosis. Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.