Abstract
A 46-year-old man who had undergone hematopoietic stem cell transplant twice because of acute lymphoblastic leukemia with recurrence presented with dyspnea, leading to a diagnosis of pulmonary arterial hypertension which was quickly and effectively treated with the phosphodiesterase type 5 inhibitor tadalafil. To our knowledge, pulmonary arterial hypertension related to hematologic malignancies requiring hematopoietic stem cell transplant is rarely reported. Importantly, the present case suggests that early diagnosis and treatment with a pulmonary vasodilator, such as tadalafil, can greatly decrease pulmonary vascular resistance in patients with severe pulmonary arterial hypertension after hematopoietic stem cell transplant and can then improve other symptoms. Accordingly, pulmonary vascular disease should be considered if respiratory symptoms develop following hematopoietic stem cell transplant, because treatment with pulmonary vasodilator may lead to significant improvement in pulmonary arterial hypertension.