Abstract
We present the case of a 55-year-old woman with Follicular Lymphoma, with basal 18F-FDG-PET/TC showing supra and infradiaphragmatic lymphatic, pleural and bone involvement. Treatment with Epcoritamab + Lenalidomide + Rituximab was iniciated with complete metabolic response (CR). Due to neutropenia, granulocyte colony-stimulating factor (G-CSF) was indicated on 02/22/23 for 5 days. A control PET/CT was performed on 02/23/23 with a pathological increase in metabolism in new-appearing mesenteric soft tissue lesions, suggestive of disease relapse. QT continued without changes and a PET/CT performed on 04/12/23 showed disappearance of the hypermetabolic mesenteric lesions. This suggests that it was a mesenteric panniculitis probably due to the use of G-CSF.