Pulmonary tumor thrombotic microangiopathy

Pulmonary tumor thrombotic microangiopathy syndrome is a rare clinicopathological entity in which tumor cell micro-emboli in the pulmonary microcirculation induced thrombotic microangiopathy. This can cause respiratory failure, and acute or sub-acute right heart failure. Histological features include micro tumor emboli in the small arteries and arterioles of the lung associated with thrombus formation and fibro-cellular and fibro-muscular intimal proliferation. The diagnosis is however extremely difficult to make before death. Thus, most of the observations reported are based on autopsy data. Very rare diagnostic observations made before death suggest the potential effectiveness of chemotherapy. Many details remain to be elucidated, interdisciplinary research is a priority with close collaboration between pathologists and clinicians to better understand this, often fatal, syndrome. It may be that the use of targeted therapies will improve the very poor prognosis allowing survival of several weeks or months after diagnosis.