Use of 18F-FDG PET-CT for Detection of Active Disease in Acute Myeloid Leukemia

A 4-year-old girl with history of acute myeloid leukemia post chemotherapy and stem cell transplant presented with pancytopenia. F-FDG PET-CT (PET-CT) showed multiple metastatic bone and extra medullary soft tissue lesions. Bone marrow biopsy after additional chemotherapy was negative. Concurrent FDG PET-CT demonstrated hypermetabolic foci in the left thigh and hand consistent with residual soft tissue disease. These lesions resolved after further treatment, but a subsequent PET-CT identified a new site of biopsy-proven chloroma. This case illustrates the important role of FDG PET-CT in identifying clinically undetectable extramedullary sites of disease, which may impact subsequent clinical management.