Thromboembolic complications unmasking membranous nephropathy: diagnostic and therapeutic challenges

Nephrotic syndrome is associated with a hypercoagulable state and can lead to serious thromboembolic complications. In patients presenting with pulmonary embolism without an identifiable provoking factor, hypoalbuminaemia and significant proteinuria should prompt consideration of underlying nephrotic syndrome. Awareness of this link is important to avoid delay in diagnosis.A woman in her 60s presented with exertional dyspnoea and pleuritic chest pain. CT pulmonary angiography confirmed bilateral pulmonary emboli and she was treated with apixaban. After discontinuing anticoagulation prematurely, she re-presented with worsening dyspnoea and fluid overload. Investigations revealed acute kidney injury, severe hypoalbuminaemia and nephrotic-range proteinuria. Repeat imaging demonstrated progression of pulmonary emboli and extensive abdominal venous thromboses. Renal biopsy confirmed phospholipase A2 receptor-positive membranous nephropathy. She was managed with anticoagulation, corticosteroids, rituximab and supportive therapy. Renal function subsequently stabilised, leaving chronic kidney disease with residual proteinuria. She remains under regular nephrology and haematology follow-up. This case emphasises the need to consider nephrotic syndrome in patients with unexplained pulmonary embolism and supports early urine protein testing as part of the initial assessment.