Immunotactoid or fibrillary glomerulopathy is a group of very rare glomerular diseases, composed of immunotactoid glomerulopathy (ITG) and non-amyloid fibrillary glomerulopathy (non-amyloid FGP) (see these terms), that are characterized by mesangial deposition of monoclonal microtubular or polyclonal fibrillar deposits. Both present clinically with nephrotic range proteinuria, hematuria and renal insufficiency leading to renal failure in many cases. ITG is more likely to manifest with underlying lymphoproliferative disease, hypocomplementemia, dysproteinemia, monoclonal gammopathy or occult cryoglobulinemia. Non-amyloid FGP is 10 times more frequent than ITG.