Disseminated microvascular pulmonary tumor embolism from non-small cell lung cancer leading to pulmonary hypertension followed by sudden cardiac arrest.

Disseminated microvascular pulmonary tumor embolism (DMPTE) is extremely rare and invariably fatal. Typical symptoms and signs of DMPTE include shortness of breath and inadequate oxygenation. Here we demonstrate a patient with unexplained progressive pulmonary hypertension followed by sudden cardiac arrest, who finally diagnosed of DMPTE pathologically under veno-arterial extracorporeal membrane oxygenation (VA-ECMO) system support. A 59-year-old gentleman was diagnosed of advanced non-small cell lung cancer with clinical stage of T3N2M1 in February 2008. His disease had been controlled well for two years under first-line clinical trial and salvage pemetrexed treatment. In early January 2010, he suffered from dyspnea on exertion gradually, although cancer progression was not proven by computed tomography (CT) scan. Transthoracic echocardiography also revealed normal heart size and function. However, he was sent to emergency room (ER) one month later due to dyspnea where pulmonary hypertension was discovered by repeated echocardiography. Follow-up CT scan was shown neither evidences of tumor progression nor pulmonary thromboembolic event in all major pulmonary vessels. Unfortunately, he was found to be unconscious suddenly at ER during urination and diagnosed as pulse-less electrical activity. Cardiopulmonary resuscitation (CPR) was initiated immediately and he was sent to intensive care unit with VA-ECMO system under the impression of cardiovascular system dysfunction. He passed away 10 days after intensive treatment. A necropsy was performed after we received the inform consent from his family. DMPTE was confirmed by pathologists. Currently, diagnosis of DMPTE is challenging and treatment is limited although advances of modern medicine. DMPTE should be kept in mind if cancer patients have dyspnea, inadequate oxygen saturation and unexplained pulmonary hypertension during their disease courses that unexpected serious consequences, like sudden cardiac arrest, may happen.