IgG4-related sclerosing disease in the kidney – a case report

A 39-year-old man presented with a left renal mass. A CT scan showed a 4.5 cm enhancing solid central left renal mass engulfing the pelvicalyceal system and the hilar blood vessels. The patient underwent a left radical nephrectomy. Macroscopically the kidney showed a cream, solid, irregular lesion occupying the central hilar region of the kidney. No necrosis or haemorrhage was present. Microscopically, there was marked fibrosis centred in the renal hilum, and extending into the perihilar fat. Associated with the extensively sclerotic fibrous connective tissue, there was a prominent plasma cell infiltrate with scattered lymphoid collections and a focal obliterative phlebitis. Immuno-histochemical examination showed the plasma cells were reactive for kappa and lambda light chains and IgG4, consistent with IgG4-related sclerosing kidney disease. IgG4 related disease is a fibroinflammatory condition that affects virtually any organ system. It is characterised by a dense lymphoplasmacytic infiltrate rich in IgG4 positive plasma cells, storiform fibrosis and often elevated serum IgG4 concentrations. The histopathological features are similar, regardless of the site of the disease. Many conditions previously confined to single organs are now considered to be part of the spectrum of IgG4-related diseases.