PMC9605840_01
Light microscopy shows a global increase of mesangial matrix, with focally mesangial hypercellularity (arrow). (a) Hyalinosis of the afferent arteriole was observed (asterisk) (H-E, 200x). (b) The glomerulus shows irregular capillary wall thickening and a cellular crescent (dashed crescent) (H-E, 200x). (c) Methanamine-silver stain (200x) shows a glomerulus with a cellular crescent (arrowhead). (d) Direct immunofluorescence showing bright granular staining of glomerular mesangium for lambda light chain (lambda++/kappa+, 200x). (e) Electron microscopy revealed large electron-dense nonorganized deposits in mesangial areas (arrow) (10000x). (f) Electron microscopy showing segmental subendothelial mesangial deposits (arrow-head) (10000x).
CRIN2022-9207282.001.jpg
PMC9605840_01_CRIN2022-9207282.001.jpg
fig1
Congo red and thioflavin staining were negative (Figures 1(a)-1(c)). On the other hand, the IF on pronase-digested paraffin-embedded (IF-P) sections showed no subendothelial or mesangial deposits of IgG, IgM, or IgA (Figure 1(d)). Electron microscopy (EM) revealed large electron-dense nonorganized deposits in mesangial and subendothelial areas (Figures 1(e) and 1(f)).