Nodular mesangial lesions, marked mesangiolysis, and fingerprint deposits of unknown origin in a patient with nephrotic syndrome: a unique combination of glomerular lesions

Abstract

A 46-year-old woman developed nephrotic syndrome at the age of 16 in 1973. On the basis of the histological findings of the first renal biopsy, she was diagnosed as having minimal change nephrotic syndrome. Initial treatment with steroid was effective, but she had several relapses during tapering of the daily dose of steroid. The second renal biopsy, performed in 1997, disclosed glomerular lobulation, mesangial proliferation, nodular mesangial lesions, and mesangiolysis. From 2001, the degree of proteinuria increased, with urinary protein being 5 g/day in January 2003, when a third renal biopsy was performed. On light microscopy, the glomerular lesions were similar to those observed in 1997. Immunofluorescence microscopy revealed coarse granular stainings for IgG, IgA, IgM, κ, λ, and C3 in the mesangial area and along the capillary walls. On electron microscopy, fingerprint structures were observed in the mesangial and subendothelial deposits. There were no characteristic fibers in the nodular lesions. On the basis of clinical and laboratory findings in this patient, we excluded disease entities in which nodular mesangial lesions, mesangiolysis, and fingerprint deposits had been reported. To our knowledge, such a unique combination of glomerular lesions has not been described previously in the literature.