Nephrotic syndrome presenting as deep vein thrombosis or pulmonary embolism

A patient presenting with a swollen left leg and pleuritic chest pain was shown to have deep vein thrombosis (DVT) by Doppler studies. He was anticoagulated but required two further admissions with swelling of both legs before a diagnosis of nephrotic syndrome was considered and confirmed. Renal biopsy showed that this was caused by membranous nephropathy. Two audits were subsequently conducted. The first was of diagnostic discharge codes for nephrotic syndrome and venous thromboembolism in south west Scotland (population 147,000) from 1997 to 2006. A diagnosis of nephrotic syndrome was confirmed in 32 patients, four (12.5%) of whom (including the index case) had presented with DVT (two) or pulmonary embolus (PE) (two). A second audit of 98 consecutive patients with Doppler-positive lower limb DVT presenting to A&E in Dumfries from July 2005 to July 2006 showed that the urine had been tested for protein in one case only. Although nephrotic syndrome remains an uncommon cause of DVT or PE, it is complicated by venous thromboembolism sufficiently frequently for the diagnosis to be considered in all patients with DVT or PE, for whom the take-home message should simply be-Don't forget to dip the urine or ignore a low serum albumin.