Widespread Skin Infiltration of Leukemia Cutis on 18F-FDG PET/CT.

A 67-year-old man experienced multiple cutaneous nodules for 3 weeks. His initial skin biopsy only showed local inflammation. However, after a 2-week anti-inflammation therapy, the skin manifestations were not improved while the leukocyte count gradually increased. FDG PET/CT revealed widespread cutaneous and subcutaneous hypermetabolic lesions in many parts of the body, and heterogeneously increased uptakes in the bone marrow. Bone marrow biopsy and second skin biopsy were performed. Pathological examination from both specimen demonstrated acute monocytic leukemia.