Rare Presentation of Lymphomatoid Granulomatosis With CNS, Pulmonary, and Musculoskeletal System Involvement on 18F-FDG PET/CT

Lymphomatoid granulomatosis is an extralymphatic angio-invasive B-cell-associated lymphoproliferative disease. It primarily affects the lungs, followed by the skin, CNS, renal, and liver, and rarely involves the musculoskeletal system. Here we report a young man with pyrexia of unknown origin in whom FDG PET/CT demonstrated an unusual combination of CNS, lung, and musculoskeletal involvement mimicking diffuse metastasis. He was diagnosed with lymphomatoid granulomatosis, grade I, on a guided biopsy of the lung nodule.