Image

Slide #

Tissue

Mag

Feature

Case 1

A

LP - PAS stain

All glomeruli are hypercellular (diffuse process)

B
C
D

HP - PAS stain

Glomeruli are hypercellular with obliteration of the capillary lumens (endocapillary proliferation). Segmental areas of the basement membranes can be observed and are normal. A few polymorphonuclear leukocytes are seen (exudation).

E

Three large subepithelial deposits (humps) are seen in the glomerular basement membrane. The remaining of the basement membrane is normal.

F

EM

One large subepithelial deposit (hump) is seen in the basement membrane related to the mesangium.

G

IF

Coarse granular pattern of positive reaction with IgG in the glomerular basement membrane ("lumpy bumpy") classical pattern of post-infectious GN.

A-B

LP - PAS stain

The glomeruli have normal number of cells. The tubules are normal (back to back).

C-D-E

HP - PAS stain

The glomeruli are normal. The capillary lumens are well visualized.

F-G

EM

The basement membranes are normal. The capillary and urinary lumens are well opened (normal). There is effacement of the epithelial cell foot processes.

A

LP - PAS stain

The glomeruli show mild increase in mesangial matrix and are otherwise unremarkable. The tubules are normal.

B-C

HP - PAS stain

The increase in mesangial matrix is better observed at this power. The capillary lumens are well visualized and the basement membranes are normal.

D-E

EM

Electron dense deposits are present in the glomerular mesangium. The basement membranes are normal.

F

IF

Positive immunofluorescence in the glomerular mesangium with IgA.

A-B

LP - PAS stain

There is focal interstitial fibrosis and tubular atrophy. Some glomeruli show segmental sclerosis.

C-D

HP - PAS stain

Glomeruli with segmental sclerosis, characterized by increase in mesangial matrix and collapse of capillary lumens.

E

EM

There is increase in mesangial matrix and diffuse effacement of the epithelial cell foot processes. Electron dense deposits are not seen.

F

EM

Area of glomerulosclerosis: There is increase in mesangial matrix with absence of capillary lumens. There is lifting of the epithelial cells from the basement membranes (clear area with "fibrillar" material).

A

LP - PAS stain

The basement membranes are slight prominent. Note the absence of increase in cellularity. The tubules are normal.

B-C

HP - PAS stain

There is slight thickening of the glomerular basement membranes (This is an early stage).

D-E

EM

Several small subepithelial electron dense deposits are seen along the glomerular basement membranes. This is better observed in E (high power). There is diffuse effacement of the epithelial cell foot processes.

F

IF

Diffuse finely granular positive reaction all along the glomerular basement membranes with IgG.

A

LP - PAS stain

All glomerular appear to be involved (increase in matrix and hypercellular). Diffuse process.

B-C-D

HP - PAS stain

The glomeruli show prominent increase in mesangial matrix and cells, segmentally the basement membranes are thickened with suggestion of splitting. One cellular crescent is observed in kodachrome C.

E-F

EM

High power of the glomerular basement membranes showing splitting (duplication) and subendothelial electron dense deposits.

A-B

HP - PAS stain

Glomeruli with prominent thickening of all basement membranes. The glomeruli are not hypercellular.

C-D

EM

There is prominent increase in mesangial matrix and prominent thickening of the glomerular basement membranes. The electron dense deposits are subepithelial and mainly intramembranous (remember that this is a late stage of a membranous GN).

A-B

HP - PAS stain

The glomeruli show thickening of the basement membranes and are only moderately hypercellular. The degree of proliferation varies in all types of proliferative GN. Kodachrome A shows segmental hypercellularity and increase in matrix.

C-D

EM

There is diffuse replacement of the glomerular basement membranes by dense deposits. This finding is classical of dense deposit disease.

A-B-C

HP - PAS stain

All glomeruli are involved with variation in degree and stage of involvement. Kodachrome A shows prominent cellular proliferation with obliteration of capillary lumens. Kodachrome B shows glomerulus with mild proliferation of the glomerular tuft but with a cellular crescent. Kodachrome C shows a glomerulus almost totally sclerosed.

D-E

EM

Electron dense deposits are seen subendothelial in the glomerular basement membranes and in the mesangium.

A-B

HP - PAS stain

The glomeruli show moderate increase in mesangial matrix. The basement membranes are normal.

C-D

EM

The basement membranes are normal. A few small electron dense deposits are seen in the mesangium.

E

IF

Positive reaction in the glomerular mesangium with Ig M C₃ and IgA.

A

LP - PAS stain

There is tubular atrophy and an interstitial mononuclear cell infiltrate.

B-C

HP - PAS stain

There is prominent thickening all along the glomerular basement membranes. A large cellular crescent is observed in kodachrome B.

D-E

EM

There is prominent increase in the glomerular mesangial matrix and prominent thickening of the basement membranes. Numerous subepithelial and intramembranous electron dense deposits are seen.

F

IF

Positive finely granular reaction all along the glomerular basement membranes with IgG and C₃.

A-B

LP, HP - PAS stain

The tubules are normal. The glomeruli show minimal changes (mild segmental hypercellularity?).

C-D-E

EM

The basement membranes are irregular and show the characteristic lamination of the lamina densa.

A

H&E stain

There is necrosis of tubules. One vessel has a fibrin thrombus. The glomeruli are congested.

B-C

HP - H&E stain

Fibrin thrombi are seen in the glomeruli.

D

EM

The capillary lumens contain red cells and fibrin.

E

EM

High power of a segment of the glomerular basement membrane showing subendothelial rarefaction and a red cell inside the basement membrane.

A-B

HP - H&E stain

The glomeruli and vessel walls are replaced by homogeneous, eosinophilic material (amyloid).

C

EM

There is increase in mesangial matrix and thickening of the basement membranes. Amyloid fibrils are not well observed at this power.

D

EM

Mesangium with amyloid fibrils.

E

EM

High power of the basement membranes with amyloid fibrils.

A

Renal medulla (papilla)

B

Renal medulla, note the absence of glomeruli

C

Renal cortex, note that the tubules are back to back. Very little intervening interstitium as compared to the medulla.

D

Normal glomerulus with normal cellularity. The capillary lumens are opened but this can be better observed with the PAS stain (PAS stain was used in the majority of the case studies because H&E is not a good stain to examine the glomeruli).

A

Interstitial fibrosis and arterioloscleroses with byaline change. Two glomenili are globally sclersed and others show nodular glomerulosclerosis.

B

High power to show the arteriosclerosis.

C-D-E

There is prominent interstitial fibrosis. The nodular glomerulosclerosis can be well observed in all the glomeruli.