A case of IgM-associated mesangial proliferative glomerulonephritis with a giant paramesangial spherical deposit.

We report a case of IgM-associated mesangial proliferative glomerulonephritis with microscopic hematuria and renal tubular dysfunction. On electron microscopy, a giant spherical deposit was observed in the glomerular paramesangial area. Deposition of C3 in the glomerular mesangial areas was not observed by immunofluorescence. IgM-associated mesangial proliferative glomerulonephritis is clinically characterized by nephrotic syndrome, mild proteinuria and/or hematuria, tubular dysfunction or renal failure, suggesting that it is considered to be a heterogeneous disorder.