Abstract
Introduction
Thrombotic microangiopathies (TMA) are characterised by thrombocytopenia, mechanical haemolytic anaemia and microvascular thrombosis. The two main TMA are thrombotic thrombocytopenic purpura (TTP) and the haemolytic uraemic syndrome. TTP is caused by reduced activity of the von Willebrand factor (VWF)-cleaving protease ADAMTS13. Patients with TTP and deficient ADAMTS13 activity in plasma have highly platelet-reactive forms of ultralarge molecular weight VWF multimers1. Haemolytic uraemic syndrome is caused by a bacterial gastrointestinal infection or complement dysregulation2. Pulmonary tumour thrombotic microangiopathy (PTTM) is a cancer-related TMA of unknown pathogenesis. It affects mainly the lung, where tumour cell microemboli and fibrocellular proliferation are found in the microvasculature, resulting in rapid and fatal pulmonary hypertension3. Recently, mediators such as platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) have been shown to play a role in PTTM and some patients have been successfully treated with combination therapy including a PDGF receptor antagonist and chemotherapy, plasma exchange being ineffective. We describe a fatal case of PTTM associated with signet-ring cell carcinoma in a young man. [ … ]
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