Diffuse Alveolar Haemorrhage Complicated by Pulmonary Metastasis of Cardiac Angiosarcoma and Kasabach–Merritt Syndrome: A Case Report

Kasabach–Merritt syndrome (KMS) is a consumptive coagulopathy caused by platelet trapping due to the distinctive endothelial structure of vascular tumours. Cardiac angiosarcoma complicated by KMS is exceedingly rare. We report the case of cardiac angiosarcoma in which diffuse alveolar haemorrhage was caused by both pulmonary metastases and KMS. Invasive mechanical ventilation with high positive end‐expiratory pressure (PEEP) temporarily achieved transfusion‐independent haemostasis. However, a biopsy could not be performed during this window, and the patient experienced a fatal outcome. In case of cardiac angiosarcoma complicated by KMS, early tissue diagnosis is critical. Strategies to achieve transfusion‐independent haemostasis such as high PEEP may create an opportunity for prompt biopsy and facilitate timely initiation of definitive treatment.