Enhanced CT and FDG PET/CT in Histiocytic Sarcoma of the Pericardium.

Histiocytic sarcoma is an extremely rare and aggressive malignant neoplasm of presumed hematopoietic origin. Lymph nodes are the most common sites of involvement. A variety of extranodal sites can be involved, particularly the gastrointestinal tract, soft tissue, skin, and spleen. Radiologic findings of histiocytic sarcoma have been rarely reported. We present a case with histiocytic sarcoma in pericardium, which is an unusual site. Enhanced chest CT showed remarkable enhancement of the tumor. On FDG PET/CT, the tumor showed intense FDG uptake.