Fulminant hemophagocytic syndrome with a high interferon gamma level diagnosed as macrophage activation syndrome.

A 26-year-old woman presented with general fatigue, persistent fever, nuchal lymphadenitis, thrombocytopenia, and liver damage. From the bone marrow finding, we diagnosed her condition as hemophagocytic syndrome. Steroid pulse therapy, cyclosporin A treatment, and combined chemotherapy generated no response. The patient showed severe mucosal bleeding, rapidly experienced multiple organ failure, and finally died of a brain hemorrhage on the 13th hospital day. Epstein-Barr virus, cytomegalovirus, human herpes virus type 6, human parvovirus B19, and herpes simplex virus were not detected. Autopsied samples of the spleen, bone marrow, and liver showed extreme proliferation of activated macrophages, so-called histiocytes, without lymphoid malignancy. The interferon gamma level at presentation was prominently high. The continuously elevated levels of ferritin and soluble interleukin 2 receptor were correlated with the catastrophic outcome. The disease in our case mimicked infantile hemophagocytic lymphohistiocytosis. However, there was neither a family history of the disease nor a mutation in the perforin gene. So, it is reasonable to categorize our case as macrophage activation syndrome. Although our patient lacked arthritis or eruption, we cannot deny the possibility that an oligoarthritis type of systemic-onset juvenile rheumatoid arthritis or, considering the patient's age, adult-onset Still disease lies at the base of our case.