FDG-PET/CT Findings in Hemophagocytic Lymphohistiocytosis

A 44-year-old man was admitted to the hospital with fever, pancytopenia, and a new rash. FDG-PET was ordered in light of nonspecific clinical, imaging, and biopsy findings. Findings included diffuse FDG uptake throughout the subcutaneous fat overlying fat stranding/haziness on CT. FDG uptake was associated with scattered subsolid/ground-glass lesions in the lungs. Splenomegaly and increased FDG uptake throughout the bone marrow were seen. Diagnostic considerations included infectious versus lymphomatous processes, and possible sites for biopsy were identified. Biopsy of a highly FDG-avid lung lesion led to a diagnosis of hemophagocytic lymphohistiocytosis secondary to peripheral T-cell lymphoma, not otherwise specified.