Rare Case of Reversible Pulmonary Arterial Hypertension Secondary to Cyclophosphamide and Doxorubicin Chemotherapy.

Pulmonary arterial hypertension (PAH), characterized as a resting mean pulmonary artery pressure greater than 25 mmHg, is due to the narrowing of the pulmonary arteries, which can be idiopathic, inherited, or drug-related. Alkylating agents, including cyclophosphamide, are a risk factor for developing the pulmonary veno-occlusive disease. Drug-induced PAH is extremely rare. A 59-year-old female with newly diagnosed invasive ductal carcinoma of the right breast and high-grade ductal carcinoma in situ of the left breast was initiated treatment with doxorubicin and cyclophosphamide. About one week after receiving the first cycle, the patient developed worsening lower extremity edema and shortness of breath. She was then hospitalized, and a transthoracic echocardiogram and coronary angiogram revealed PAH. The team then changed the breast cancer treatment regimen to Taxol and carboplatin, and PAH was resolved in a follow-up echocardiogram after five months. This report has described the first case of PAH directly related to cyclophosphamide and doxorubicin. It is imperative to promptly recognize this rare but important side-effect as early diagnosis and response can potentially reverse the disease progression.