Recent-onset myelodysplastic syndrome mimicking acute leukemia during infection.

A previously healthy 74-year-old patient without a prior history of hematological disease presented with an acute respiratory infection. Peripheral pancytopenia led us to perform a bone marrow biopsy, and the diagnosis of undifferentiated acute myelogenous leukemia (AML, 61% blasts) was made. Following antibiotic treatment and resolution of the infection, the blast count in the bone marrow fell to 2%, leaving a clinicopathologic picture consistent with myelodysplastic syndrome (MDS, French-American-British type refractory anemia), and the patient survived for a total of 16.5 months following the initial presentation with cytokine support. A preterminal blast proliferation occurred during a bacterial ear infection and rapidly responded to a withdrawal of cytokine support, antibiotic therapy, and hydroxyurea. The patient succumbed ultimately to an apparent myocardial infarct. Clinicians should consider transient acceleration of MDS in their differential diagnosis when confronted with apparent AML and acute infection.