Membranous Nephropathy.

Primary

Secondary: chronic hepatitis B, syphilis, schistosomiasis, malaria, lung and colon cancer, melanoma; SLE, gold, mercury, penicillamine, captopril, NSAIDs

diffuse thickening of the GBM

effacement of foot processes

Immunofluorescence microscopy shows typical granular deposits of immunoglobulins and complement along the GBM

Membranous glomerulonephritis. A, PAS stain. Note the marked diffuse thickening of the capillary wall without an increase in the number of cells.