Lobular membranoproliferative glomerulonephritis with organized microtubular monoclonal immunoglobulin deposits associated with B cell small lymphocytic lymphoma.

Sir, Fibrillary glomerulonephritis (FGN) and immunotactoid glomerulopathy (ITG) are well known glomerular diseases with Congo-red-negative deposits [1–4]. While FGN is characterized by randomly arranged microfibrils around 20 nm in diameter with no underlying systemic disorder, ITG is defined by orderly arranged microtubular deposits, usually >30nm in diameter with a hollow core; patients with ITG tend to have underlying lymphoproliferative diseases. Microtubular monoclonal immunoglobulin deposits with a diameter smaller than that commonly observed in ITG have been described in a few patients with lymphoproliferative disorders, and Touchard et al. coined the term ‘GOMMID’ for such glomerulonephritis with organized microtubular monoclonal immunoglobulin deposits [5,6]. We report here a patient with nephrotic syndrome due to GOMMID following B-cell malignant lymphoma associated with IgG-k monoclonal gammopathy. Interestingly, although the patient developed AL amyloid deposition (k type) in a cervical lymph node, no amyloid was recognized in the kidney.