Histology

Question 1

Causes of Granular IgG on IF

Answer 1

Primary membranous, SLE

Question 2

Causes of Linear IgG on IIF

Answer 2

Anti GBM disease, diabetes, monoclonal immunoglobulin deposition disease

Question 3

Causes of mesangial IgG staining

Answer 3

Lupus, IgA

Question 4

Features of membranous Nephropathy

Answer 4

Thickened BM, Spikes on silver stain, subepithelial deposits
IgG4 subclasses

Note - mesangial deposits more likely in secondary MN

Question 5

Features of FSGS

Answer 5

> 70% foot process effacement

Question 6

Causes of subendothelial deposits

Answer 6

Lupus (class3-4), MPGN, cryoglobulinaemia

Question 7

Causes of intramembranous deposits

Answer 7

Dense deposit disease, C3 factor

Question 8

Features of transplant glomerulopathy

Answer 8

Double contouring on silver stain

Question 9

Features of Amyloid

Answer 9

Congo red, apple bifringe, PAS negative - look pale

Question 10

Features associated with IgA

Answer 10

KM55 - positive on renal Bx
Glomerulosclerosis
Tubulointerstitial fibrosis
Mesangial hypercellularity
Endocapillary hypercellularity
Crescents

Question 11

Features of post infection GN on renal Bx

Answer 11

Diffuse proliferative GN
Hypercellularity - monocytes and neutrophils
IIF - dominant C3 staining. some IgG
Starry sky pattern
Irregular mesangial and capillary wall pattern
SubEpitheilial humps / deposits

Question 12

C3 Glomeulonephritis

Answer 12

C3 deposits in the mesangium and subendothelial space

Question 13

Name 5 Lupus classes on histology

Answer 13

The standard classification divides these into five different patterns:

I - No disease
II - Mesangial proliferation
III - Focal proliferative
IV - Diffuse proliferative
V - Membranous.
VI = Sclerosis

Question 14

Histological features of Membranoproliferative glomerulonephritis aka Mesangiocapillary GN

Answer 14

Double contour / splitting of GBM = Tram Tracks
mesangial and endothelial cell proliferation,
expansion of the mesangial matrix
thickening of the peripheral capillary walls.

Question 15

Features seen with BK infection

Answer 15

Cd4 positive staining
SV -40 antigen seen in tubular epithelial cells.
Inclusion bodies

Question 16

Features of Lupus

Answer 16

Proliferation of capillaries and obliteration of capillary loops - capillaries stain deep red =”wire loop” lesion
Full house immunology
increase in mesangial matrix volume
Subendothelial deposits
Mesangial fingerprinting

Question 17

Features of Alports on renal Bx

Answer 17

Loss of podocytes
Thin GBM - look’s like ‘basket weave’
Splitting of lamina densa
Looks similar to FSGS

Question 18

When do you see Kimmelstiel-Wilson lesions

Answer 18

Depict nodular glomerulosclerosis
Seen in diabetic related kidney disease.

Question 19

When do you see inclusion body’s versus owls eyes

Answer 19

Owl’s eyes = CMV
Inclusion bodys = BK (seen with SV 40)

Question 20

Features of Oxalate nephropathy on renal Bx

Answer 20

Calcium oxalate deposition within the tubular epithelial cells and lumen
Crystals appear translucent
Look like ‘fan-like’ / sheaf like / sunburst
Strongly birefringent under polarized light

Question 21

Features of glomerular nephropathy as they occur

Answer 21

1) Tubular cell hypertrophy - causes hyperfiltration
2) Thickening of GBM
3) Thickening of tubular membrane
4) Kimmelsteil- wilson nodules
5) Glomerular microaneurysums

Question 22

When do you see tubular reticulocyte inclusion bodies

Answer 22

SLE
HIV
interferon

Question 23

Difference between hyaline casts and fractured casts

Answer 23

fractured casts - cells around the edge due to it being an inflammatory process. Hyaline cells - no cells around the edge

Question 24

Differentials for increased inflammatory cells in transplant Bx

Answer 24

Tcell mediated rejection / cellular rejection
Viruses - BK

Question 25

Features on Bx in Light chain cast nephropathy

Answer 25

Aka myeloma cast nephropathy Kappa on IF Fractured casts

Question 26

Features of dense deposit disease

Answer 26

Intramembranous, sausage like deposits Common cause is C3 nephritic factor- antibody which inhibits Factor H, allowing uncontrolled activation of the alternative pathway of complement. Causes very low levels of serum C3.

Question 27

Causes of cresents on renal Bx

Answer 27

ANCA IgA /HSP Lupus Anti GBM Post infectious GN

Question 28

Features of IgG4 on renal biopsy

Answer 28

IgG4 positive Plasma cell lymphocytic infiltration in the tubulointerstitial compartment *Storiform fibrosis*

Question 29

Features of Class 2-3-4-5 lupus

Answer 29

Class 2 = Mesangial proliferation Class 3 = <50% gloms affected Class 4 = >50% gloms affected Class 5 = Subepithelial deposits

Question 30

Features of acute tubular necrosis on renal Bx

Answer 30

Flattening of tubular cells Intratubular cast formation History of muddy brown / granular casts