Pathology of glomerular deposition diseases and fibrillary glomerulopathies associated with paraproteinemia and haematopoietic disorder.

The primary glomerulopathies with a deposit of ultrastructural fibrillary structure, which are negative for Congo-red stain but positive for immunoglobulins, include fibrillary glomerulonephritis and immunotactoid glomerulopathy. Several paraproteinemias, including cryoglobulinemia, monoclonal gammopathy and light chain deposition disease as well as haematopoietic disorders including plasmacytoma, plasma cell dyscrasia and B cell lymphoproliferative disorders involve glomerulopathy with an ultrastructural fibrillary structure. A rare glomerulopathy with fibrillary structure showing negative stain for Congo-red and for immunoglobulins has been also reported. The pathological diagnoses of these glomerulopathies with ultrastructural fibrillary deposits can include either glomerular diseases, or paraproteinemic diseases, or haematopoietic diseases. The terminology is still confusing when glomerular diseases can be combined with paraproteinemic diseases and/or haematopoietic diseases. Therefore, the generic term, 'glomerular deposition disease', has been proposed by pathologists with a requirement for clinicians to detect autoantibodies, paraproteins and to carry out a bone marrow check. An attempt has been made to elucidate the correlation among the glomerular deposition disease, paraproteinemia and haematopoietic disorder.