How to Diagnose and Treat Pulmonary Tumor Thrombotic Microangiopathy

We report here a 70-year-old female patient with a history of breast cancer who presented with dyspnea that had lasted for 2 weeks following a long-distance trip by bus. She was at first suspected of having a pulmonary embolism given the typical presentation, elevated D-dimer level, and enlargement of the right-side heart. However, her systemic condition deteriorated despite the initiation of anti-coagulation therapy. Given the absence of a major thrombus in the pulmonary major arteries but multiple low perfusion lesions in the periphery of the lungs, refractoriness to conventional therapy, an increase in tumor markers, and anaplastic cells demonstrated by aspiration cytology from the pulmonary artery, we diagnosed her as pulmonary tumor thrombotic microangiopathy (PTTM). She died on day 23 due to respiratory failure despite administration of inotropes and prostaglandin I2. The patient had an obvious history of malignancy, but we should emphasize that PTTM can develop even in patients with early-stage or completely cured malignancies. Although an early and definite diagnosis of PTTM is currently challenging, an optimal diagnostic and therapeutic strategy is warranted.