Disseminated histoplasmosis presenting as thrombotic microangiopathy.

Background: Thrombotic microangiopathies (TMA) are systemic vasoocclusive disorders associated with significant morbidity and mortality. Rapid and reliable diagnosis of TMA is critical. The diagnosis is complicated by a lack of objective and sensitive laboratory testing as well as multiple concurrent diseases, including infectious processes.

The usefulness of the aspirate differential count in cases of nonhematologic neoplasia.

A standard bone marrow examination may be done in patients with a known nonhematologic malignancy in order to evaluate the presence or absence of metastatic disease. A 300-cell-count differential of the aspirate is often performed in these cases. However, the clinical utility of the differential count has never been assessed.