Deep venous thrombosis and pulmonary artery embolism in high-grade non Hodgkin's lymphoma: incidence, causes and prognostic relevance.

To analyse incidence, risk factors, causes and prognostic significance of venous thromboembolism (VTE) in high-grade non-Hodgkin's lymphoma (HG-NHL) a prospective clinical trial (N = 593), also undertaken to analyse other aspects of HG-NHL, a study of haemostasis (N = 25) and a post-mortem analysis (N = 70) were performed. Clinical analysis documented a 6.6% incidence of VTE, and 77% of all cases occurred before or within the first 3 months of chemotherapy. Ann Arbor stage IV and B-mediastinal clear cell histology were risk factors for VTE, while rapid changes in tumour load or application of consolidation chemotherapy were not. Vessel compression by HG-NHL was the leading cause of VTE, whereas a significant (paraneoplastic or chemotherapy-induced) thrombophilic state was not disclosed by haemostatic tests. While VTE-related fatality was found to be low in the clinical trial (1.7%) and at necropsy (8.5%), the occurrence of VTE was associated with an unsatisfactory response of HG-NHL to chemotherapy and a high incidence of treatment-related mortality due to diffuse alveolitis. Thus, fatal VTE in HG-NHL is rare, but VTE is associated with an unfavourable clinical course of HG-NHL.