Hypermetabolic Lymphadenopathy on PET CT in Systemic Lupus Erythematosus: A CaseReport

Background: New onset and active Systemic Lupus Erythematosus (SLE) may be infrequently associated with diffuse lymphadenopathy. This is often worrisome for malignancy in which F18/FDG PET scanning is typically obtained as part of a neoplastic workup. Results are often difficult to interpret and resemble lymphoma in many instances. There is sparse literature describing systematic differences in inflammation versus neoplasm pertaining to SLE in this context. Case Series: We have reviewed F18/FDG PET/CT imaging and histology from three patients with hyper metabolic lymph nodes who were found to have benign pathology in the setting of active SLE. Conclusion: FDG PET scanning is an imaging modality that is infrequently used as a means to non-invasively assess inflammation in rheumatic diseases. Further studies are needed to determine metrics for delineating benign inflammation versus neoplasm based on standard uptake units. However, lymph node biopsy should remain the gold standard for diagnosis in this particular patient population. Keywords: PET scan; Systemic Lupus Erythematosus; Lymphadenopathy