Overview
Recognise evolving systemic coagulation activation in cancer, distinguish bleeding- and thrombosis-dominant phenotypes, treat the malignant or infective trigger and use components and anticoagulation according to clinical need.
Disseminated intravascular coagulation is a clinicopathological syndrome rather than a single laboratory result. Malignant cells, infection or tissue injury generate systemic thrombin, forming fibrin in small and large vessels while consuming platelets and clotting factors. Secondary fibrinolysis produces high D-dimer and contributes to bleeding. The phenotype depends on the driver: APL commonly causes severe hyperfibrinolytic bleeding; metastatic mucinous adenocarcinoma may produce slower thrombosis-dominant DIC; sepsis can create rapidly progressive microvascular organ failure.
Diagnosis requires a compatible cause and repeated tests. Platelets fall, PT commonly prolongs, fibrinogen may fall and D-dimer rises, but early fibrinogen can remain normal or high as an acute-phase reactant. APTT may be normal or shortened initially. The blood film can show schistocytes, although heavy fragmentation suggests thrombotic microangiopathy. The ISTH overt-DIC score combines platelet, PT, fibrin markers and fibrinogen and is useful when applied serially; it does not excuse treatment delay in a bleeding patient with a strong APL or sepsis picture.