Unsuspected early necrotizing fasciitis identified by 18F-FDG PET imaging in a patient with acute myeloid leukemia

Necrotizing fasciitis is a part of a spectrum of necrotizing soft tissue infections that usually follow a surgical intervention or a chronic / acute medical illness. Diagnosis is often based on symptoms which classically start within hours after an injury. There are no reports on the use of PET/CT in this condition. Sparing reports of its association in patients with malignancy (Ca of colon and rectum) are available. Here we present a young lady in remission from acute myeloid leukemia (AML) with sudden onset right knee pain and fever after a trivial foot injury. Clinically an osteomyelitis or acute septic arthritis was suspected, although the location is not appropriate for osteomyelitis. 99mTc-MDP bone scan was performed followed by 18FFDG PET. 18F-FDG PET scan was incremental in diagnosing subcutaneous infection around right knee even before appearance of an ulcer or skin erosion. Tissue culture confirmed necrotizing fasciitis. This is the first case report highlighting necrotizing fasciitis in a patient with AML.