Glomerular basement membrane showing "tram-track" appearance is seen in

Membranoproliferative Glomerulonephritis (MPGN) type 1:MPGN is best considered a pattern of immune-mediated injury rather than a specific disease. The glomeruli are large and hypercellular. The glomeruli have an accentuated "lobular" appearance due to the proliferating mesangial cells and increased mesangial matrix. The GBM is thickened, and often shows a "double contour" or "tram-track" appearance, especially evident in silver or PAS stains. This is caused by "duplication" of the basement membrane (also commonly referred to as splitting), usually as the result of new basement membrane synthesis in response to subendothelial deposits of immune complexes.Ref: Robbins and Cotran Pathologic Basis of Disease; 9th edition; Chapter 20; The Kidney; Page no: 920