When deep venous thrombosis fails to respond to therapy.

BACKGROUND Deep venous thrombosis in primary care is usually treated with rest, analgesics, intravenous or low-molecular-weight heparin, and coumadin. In some cases, however, a less familiar course of diagnosis and management is required. METHODS We describe the case of a 53-year-old truck driver who had an acute deep venous thrombosis of his right lower extremity, which failed to respond to routine therapy with heparin and warfarin. A literature search was undertaken to research the differential diagnosis and management of deep venous thrombosis and to review specifically the role of venal caval filters and inherited thrombotic disorders and occult cancer in this context. RESULTS AND CONCLUSION The ultimate diagnosis in our patient appeared to be signet ring cell cancer of the colon that had metastasized to the right thigh. This case is an example of the inherent limitations of even an aggressive diagnostic and therapeutic approach to the entity of refractory deep venous thrombosis.