Bone marrow necrosis discovered in a patient with suspected thrombotic thrombocytopenic purpura.

A 48 year-old white man was hospitalized for evaluation of back pain. At time he reported that he had been in excellent health until three months before his hospitalization when he noticed difficulty walking when he got out of his car following a long trip. He said that “it just felt as though my legs wouldn’t move very well”. He did not see a doctor since this problem resolved within several days. Three weeks before his hospitalization, he thought he “had a viral illness” with cough and fatigue that persisted, together with subsequent abdominal discomfort. His primary care physician noted that his platelet and white blood cell counts were low which he attributed to a viral infection. An abdominal ultrasound reported minimal splenomegaly. He was treated with antibiotics and prednisone; all of his symptoms resolved and his platelet count increased. One week before his hospitalization he developed low back pain which made walking difficult. He also had fever and sweats. When these symptoms persisted he was admitted to the hospital. His physical examination was normal. His spleen was not palpable; he had no lymphadenopathy; his neurologic examination, including his gait, was normal. He had no back tenderness. His platelet count was 23,000/µL; white blood cell count, 3700/µL with a normal differential; hemoglobin, 13.5 gm/dL; creatinine, 1.7 mg/dL; LDH, 1737 U/L (normal, <190 U/L). Coagulation tests were normal; fibrinogen was 858 mg/dL. Examination of the peripheral blood smear demonstrated schistocytes and normal white cell morphology. Thrombotic thrombocytopenic purpura (TTP) was suspected because of the thrombocytopenia, red cell fragmentation, high serum LDH and creatinine, the history of fever, the possibility that the difficulty walking may have been a neurologic manifestation of TTP, and – most important – no apparent alternative etiology. Treatment with plasma exchange (PEX) and corticosteroids was begun.