Pulmonary arterial hypertension in an 80-year-old man with long-term use of cyclophosphamide.

An 80-year-old man diagnosed with primary macroglobulinemia 7 years earlier had been treated with cyclophosphamide, following which he developed dyspnea on exertion. Cyclophosphamide was discontinued. The patient's dyspnea, however, failed to improve. Right heart catheterization (RHC) revealed precapillary pulmonary hypertension (PH). He was transferred to our institution for further examination. Prior use of cyclophosphamide was the patient's only risk factor for PH, and cyclophosphamide use was considered as a possible cause of PH in this case. He was treated with tadalafil and dyspnea gradually improved. A follow-up RHC exhibited improvement in mean pulmonary arterial pressure and pulmonary vascular resistance.