IgM nephropathy complicated by cerebral venous sinus thrombosis: a case study

BACKGROUND: IgM nephropathy is a rare disease with variable clinical presentations and is an unusual cause of nephrotic syndrome. Histopathological findings typically include mesangial hypercellularity with IgM and complement deposition, though the spectrum may range from normal glomeruli through to focal and segmental glomerulosclerosis. Thromboembolism is a well recognised complication of nephrotic syndrome, but cerebral venous sinus thrombosis is rarely described. CASE PRESENTATION: This is the case of a 23-year-old male presenting with the nephrotic syndrome, whose initial renal biopsy was consistent with minimal change disease. Complete remission was achieved with prednisone, however multiple relapses and steroid dependence prompted re-biopsy, the results of which were more consistent with IgM nephropathy. His last relapse was complicated by cerebral venous sinus thrombosis. He then received rituximab and a weaning course of prednisone to again enter remission. CONCLUSIONS: This case highlights the need to consider IgM nephropathy in the differential diagnosis of nephrotic syndrome. Additionally, it emphasises the risk of thrombosis in patients with severe nephrosis.