Malignant histiocytosis in a patient with sickle cell anemia: CT findings.

Malignant histiocytosis is a rare systemic disorder, characterized by progressive, invasive proliferation of atypical histiocytes. It is synonymous with the disease entity "histiocytic medullary reticulosis" initially described by Scott and Robb-Smith (Lancet 1939;194-8). To date, there have been slightly more than 100 cases reported in the literature. Although the radiographic features of malignant histiocytosis have been reported, to our knowledge there has not been any computed tomography (CT) description of the findings of this disease entity. The purpose of this report is to describe the serial CT findings of an unusual case of malignant histiocytosis in a patient with sickle cell anemia, presenting with weight loss and hepatosplenomegaly.