Phlegmasia cerulea dolens (PCD) is an aggressive and life-threatening form of venous thrombosis complicated by ischemic necrosis. Massive thrombosis extends to collateral veins resulting in venous congestion with fluid sequestration in the interstitium causing collapse of arterioles, which progresses to ischemia and, if severe, circulatory collapse and shock. The mortality rate for PCD is as high as 40%, especially when gangrene develops. PCD has been associated with acquired thrombophilias, including malignancy and antiphospholipid syndrome (APS). We present a unique case of a patient with PCD refractory to anticoagulant and thrombolytic therapy, whose fulminant course was attributed to concurrent cholangiocarcinoma and antiphospholipid antibodies identified by a positive lupus anticoagulant assay. This case highlights the importance of uncovering precipitating causes of thromboembolism, which may offer prognostic information and may necessitate therapy beyond anticoagulation and thrombolysis to reduce the morbidity of PCD. The current literature on PCD and APS, along with their associations with malignancy, is reviewed.