Pulmonary tumour thrombotic microangiopathy: a rare but underappreciated complication of malignancy

A 36-year-old man presented with a syncopal episode and worsening dyspnoea over the previous 3 days. He had recently been diagnosed elsewhere with poorly differentiated metastatic carcinoma. Our examination and imaging revealed severe right heart failure and pulmonary hypertension. He died within hours of his presentation. A subsequent autopsy revealed a diagnosis of pulmonary tumour thrombotic microangiopathy, which is mostly associated with carcinomas and is characterised by microemboli formation in the pulmonary vasculature.1 The histopathology from autopsy showed an arteriole with a tumour embolus associated with the fibrin (Figure, A) and fibrous intimal hyperplasia nearly occluding the lumen of these vessels (Figure, B). The acute and rapid nature of the condition makes antemortem diagnosis a significant challenge, although present in 3.3% of cases of carcinomas at post mortem examination.1^,2 While there are no guidelines on management, case series describe imatinib, chemotherapy or targeted therapy aimed at the primary malignancy, or corticosteroid therapy as potential options.1^,2