[Disseminated toxoplasmosis confirmed by tachyzoites and cysts in bone marrow smear after cord blood transplantation]

The patient was a 48-year-old man with relapsed acute myelogenous leukemia who underwent a second umbilical cord blood transplantation. Four months after the transplantation, he was admitted to our hospital due to immobility. Computed tomography and magnetic resonance imaging showed multiple nodules in the cerebrum and lungs, and blood tests revealed pancytopenia and hyperfibrinolysis, which suggested hemophagocytic syndrome. Antibacterial and antifungal therapy was started, but organ failure progressed. Due to progression of pancytopenia, hyperfibrinolysis, and fever, a bone marrow examination was performed on the 8th day of admission to assess for hemophagocytic syndrome. The bone marrow smear showed Toxoplasma gondii tachyzoites and cysts. The patient had not been given trimethoprim/sulfamethoxazole due to a drug allergy, and thus was administered trimethoprim/sulfamethoxazole immediately. However, he developed multiple organ failure and died on the 9th day of admission. We report a rare case of disseminated toxoplasmosis after allogeneic hematopoietic stem cell transplantation in which Toxoplasma gondii tachyzoites and cysts were identified in the bone marrow smear.