Autoimmune lymphoproliferative syndrome (ALPS) is a rare immune dysregulatory condition, usually presenting in childhood with massive lymphadenopathy, splenomegaly, and an increased incidence of lymphoma. Methods to differentiate between benign ALPS adenopathy and lymphoma are needed. To this end, we evaluated the usefulness of FDG PET.
We prospectively evaluated 76 ALPS/ALPS-like patients including FS-7–associated surface antigen (FAS) germline mutation with (n = 4) and without lymphoma (n = 50), FAS-somatic (n = 6), ALPS-unknown (n = 6), and others (n = 10) who underwent FDG PET. Uptakes in 14 nodal sites, liver, and spleen were determined.
In 76 ALPS patients, FDG PET showed uptake in multiple nodal sites in all but 1 patient. The highest SUVmax values in FAS mutation without lymphoma, FAS mutation with lymphoma, FAS somatic, ALPS-unknown, and other genetic mutations were a median (range) 9.2 (4.3–25), 16.2 (10.7–37.2), 7.6 (4.6–18.1), 11.5 (4.8–17.2), and 5.5 (0–15.3), respectively. Differences between uptake in the FAS group with and without lymphoma were statistically significant, but overlapped, making discrimination between individuals with/without lymphoma impossible. The spleen:liver uptake ratio was greater than 1 in 82% of patients.
While statistically significant differences were observed in FAS mutation ALPS with and without lymphoma, the significant overlap in FDG uptake and visual appearance in many patients prevents discrimination between patients with and without lymphoma. Similar patterns of FDG biodistribution were noted between the various ALPS subgroups.
From the *Nuclear Medicine Division, Department of Radiology & Imaging Science, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, MD
†Currently at Memorial Sloan Kettering Cancer Center and Weill Cornell Medical Center, New York, NY
‡Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases
§Department of Radiology &Imaging Sciences, Warren Grant Magnuson Clinical Center, National Institutes of Health
∥Hematopathology Section, Laboratory of Pathology, National Cancer Institute, Bethesda, MD.
Received for publication May 31, 2019; revision accepted August 5, 2019.
Conflicts of interest and sources of funding: The authors have no conflicts of interest. This work was supported by the National Institute of Allergy and Infectious Diseases, the National Cancer Institute, and the Nuclear Medicine Department, Hatfield Clinical Center, National Institutes of Health.
Correspondence to: Jorge A. Carrasquillo, MD, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY 10065. E-mail: email@example.com.
Online date: October 31, 2019