Rare forms and atypical locations of cancer-associated thrombosis

Cancer-associated thrombosis is traditionally viewed mainly in the context of venous thromboembolism, however, the spectrum of thrombotic complications is markedly broader in patients with cancer. Apart from deep vein thrombosis and pulmonary embolism, it may include arterial thrombosis, cerebral venous thrombosis, splanchnic vein thrombosis, ovarian and renal vein thrombosis, as well as treatment- and immune-associated thrombotic disorders. The aim of this review is to discuss rare forms and atypical sites for cancer-associated thrombosis by covering their clinical significance, pathogenetic basis, association with anticancer therapy as well as concomitant prothrombotic conditions. The article discusses the main mechanisms underlying tumor-associated hypercoagulability, including the role for endothelial dysfunction, platelet activation, neutrophil extracellular traps, and thromboinflammation. Special attention is paid to arterial thrombosis, breast cancer therapy, cerebral venous thrombosis, abdominal vein thrombosis, COVID-19-associated coagulopathy as well as vaccine-induced immune thrombotic thrombocytopenia. Timely recognition of such conditions requires a multidisciplinary approach, proper imaging, and assessment of tumor-, patient-, and treatment-related risk factors.

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