The role of the bone marrow examination in the diagnosis of immune thrombocytopenic purpura: case series and literature review.

The need for a bone marrow examination was assessed in patients with clinical and laboratory features consistent with ITP; the literature was reviewed. The records of all patients undergoing a bone marrow examination between January 1988 to January 1998 were retrospectively reviewed to determine which were motivated by the suspicion of ITP. Data were collected from hospital and outpatient medical and pathology records. Eighty-six patients with isolated thrombocytopenia (i.e., normal white blood cell count, hemoglobin, peripheral smear and clotting studies) were studied. The bone marrow was consistent with ITP in 82 patients, (i.e., normal or increased megakaryocytes and other hemopoietic lineages normal.) Four patients had decreased megakaryocytes, but all patients responded to corticosteroids. All 86 patients were followed up for a median of 22 months after bone marrow aspiration (range, 2-76 months.) During that time, none of the patients developed features to suggest an alternative diagnosis to ITP. The initial clinical and laboratory findings of 99 patients with acute leukemia were also reviewed; all had features atypical of ITP. These data suggest that routine performance of a bone marrow examination for the diagnosis of ITP is not necessary, provided that a thorough history and physical examination are performed and that the complete blood cell count, peripheral blood smear, and routine clotting studies show no abnormalities apart from thrombocytopenia. The findings of seven prior retrospective studies, two in adults and five in children are consistent with the previous findings. However, the value of marrow investigation in ITP remains unresolved and data from a large prospective study would be helpful.