A Case of Recurrent Breast Cancer Identified by Pulmonary Tumor Thrombotic Microangiopathy.

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare, cancer-related, pulmonary complication that causes hypoxia and pulmonary hypertension. We report on a 42-year-old woman who was diagnosed with recurrent breast cancer that was detected due to the presence of PTTM. Eleven months after surgery for heterochronous bilateral cancer of the left breast, she developed progressive dyspnea but computerized tomography showed no pulmonary thromboembolism, and a transthoracic echocardiography revealed mild pulmonary hypertension. She was diagnosed with PTTM by cytology from pulmonary artery catheterization and perfusion lung scintigraphy. Also, the patients complained of back pain after admission, bone scintigraphy showed multiple bone metastases. Despite the early diagnosis of PTTM, her platelet count decreased, her performance status rapidly deteriorated, and her dyspnea worsened. Thus, we could not treat her with chemotherapy. She died due to respiratory failure 19 days after admission. To the best of our knowledge, this is the first report of recurrent breast cancer identified by the manifestation of PTTM. Although PTTM is a rare phenomenon, it should be considered in the differential diagnosis of acute dyspnea or pulmonary hypertension in patients with breast cancer. Furthermore, upon diagnosis, the patient should be referred to a cardiologist as soon as possible.