Chronic thromboembolic pulmonary hypertension complicated by a cavitating lung infection caused by Mycobacterium intracellulare.

A 35-year-old man with a six-month history of progressive exertional dyspnea was referred to our institution. He had been diagnosed with Mycobacterium intracellulare pulmonary infection with lung cavitation two years earlier, and was being followed up without any medications. After being referred to our hospital, he underwent computed tomographic pulmonary angiography, which indicated a pulmonary thrombus and lung cavitation. Furthermore, right heart catheterization confirmed pulmonary hypertension, and we made a diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH). Following successful pulmonary endarterectomy, the patient's symptoms and hemodynamics were significantly improved, with the disappearance of lung cavitation. It is important to suspect CTEPH in patients with unaccountable infectious lung cavities.