Cutaneous necrosis as a terminal paraneoplastic thromboembolic event in a patient with non-Hodgkin's lymphoma

Thrombotic complications in non-Hodgkin's lymphoma often originate in the large veins. We describe a patient with refractory advanced high-grade lymphoma who presented with the rare complication of extensive cutaneous necrosis due to thrombosis of dermal vessels; there was also a recent new peak of monoclonal IgM-kappa protein. Direct immunofluorescence demonstrated immune deposits with complement in the dermal vessel wall. Based on these observations and on published data, we suggest that these complexes were the trigger for the thrombotic events and that the monoclonal IgM acted as xenoreactive antibodies, initiating a cascade of events. The first step of this cascade was activation of the complement and the membrane attack complex, which caused secretion of IL-1 alpha by endothelial cells, followed by overexpression of tissue factor on the surface of the dermal vessel wall endothelium. Dermal vessel thrombosis was the final event in this cascade.