A 54-Year-Old Man With Pancytopenia

A 54-year-old man presented for evaluation of new-onset pancytopenia.He had a distant history of viral myocarditis and was taking lisinopril, carvedilol, furosemide, aspirin, and a multivitamin.No new medications had been started in the past year.Twelve years prior, he underwent uncomplicated Roux-en-Y gastric bypass (RYGB) surgery.Review of systems was notable for fatigue and negative for fever, night sweats, weight loss, dyspnea, or abnormal bleeding.Examination revealed temperature of 36.7°C;heart rate, 91/min; blood pressure, 120/70 mm Hg; and body mass index, 20.1 (calculated as weight in kilograms divided by height in meters squared).He was well-appearing with conjunctival pallor but no petechiae, no hepatosplenomegaly, and a normal neurologic examination.Laboratory evaluation showed a white blood cell count of 1.7 × 10 3 /μL with an absolute neutrophil count of 0.17 × 10 3 /μL; hemoglobin level, 7 g/dL with mean corpuscular volume of 103 fL (reticulocyte index, 0.94); and platelet count, 116 × 10 3 /μL.Results of a complete blood cell count from 8 months prior were normal.Results of serum protein electrophoresis were normal, as were levels of lactate dehydrogenase, ferritin, folate, vitamin B 12 , and thyroid-stimulating hormone.A computed tomography (CT) scan of the abdomen showed no lymphadenopathy, masses, or hepatosplenomegaly.Peripheral blood smear showed occasional pseudo Pelger-Huet cells and rare teardrop cells.Histopathologic examination of bone marrow aspirate revealed a normocellular marrow and dyserythropoiesis with vacuolized and dysplastic erythroid precursors (Figure , panel A), leftshifted granulocytic maturation with vacuolized granulocytic precursors, ring sideroblasts (Figure, panel B), and no increase in blasts.Cytogenetic studies from the bone marrow did not reveal any abnormalities.