Table 3.

Some examples of GN diagnoses

(1) IgA nephropathy

Primary diagnosis: IgA nephropathy

Pattern of injury: diffuse mesangial and focal segmental endocapillary proliferative and sclerosing GN

Score/grade: Oxford classification: M1 E1 S1 T1

Additional features: focal global glomerulosclerosis (20%), moderate tubular atrophy and interstitial fibrosis (30%), mild arteriosclerosis and hyaline arteriolosclerosis

Secondary diagnoses: diabetic nephropathy, mild

(2) Lupus nephritis

Primary diagnosis: (1) lupus nephritis and (2) thrombotic microangiopathy

Pattern of injury: diffuse proliferative and sclerosing GN with focal (10%) cellular crescents

Score/grade: ISN/RPS class IV-G (A/C)

Additional features: thrombotic microangiopathy associated with antiphospholipid antibodies/clinical, focal global glomerulosclerosis (10%), mild tubular atrophy and interstitial fibrosis (10%), moderate arteriosclerosis, and moderate hyaline arteriolosclerosis

(3) Hepatitis C–associated immune–complex GN

Primary diagnosis: immune-complex GN

Pattern of injury: membranoproliferative GN

Additional features: with features of cryoglobulinemic GN (hepatitis C/clinical), focal global glomerulosclerosis (20%), moderate tubular atrophy and interstitial fibrosis (30%), moderate arteriosclerosis, and moderate hyaline arteriolosclerosis

(4) Infection-related GN

Primary diagnosis: IgA–dominant infection–related GN

Pattern of injury: diffuse exudative GN

Additional features: associated with S. aureus cellulitis infection/clinical, focal global glomerulosclerosis (30%), moderate tubular atrophy and interstitial fibrosis (30%), moderate arteriosclerosis, and moderate hyaline arteriolosclerosis

Secondary diagnoses: diabetic nephropathy, moderate

(5) ANCA GN

Primary diagnosis: proteinase 3-ANCA GNa

Pattern of injury: necrotizing and crescentic GN

Prognostic class: focal (≥50% normal glomeruli)

Additional features: clinicopathologic features of granulomatosis with polyangiitis (proteinase 3 and cytoplasmic ANCA/clinical), focal global glomerulosclerosis (10%), mild tubular atrophy and interstitial fibrosis (10%), mild arteriosclerosis, and moderate hyaline arteriolosclerosis

(6) Anti-GBM GN

Primary diagnosis: anti-GBM GN

Pattern of injury: necrotizing and crescentic GN, severe

Additional features: clinicopathologic features of Goodpasture syndrome (anti-GBM antibody/clinical), focal global glomerulosclerosis (40%), moderate tubular atrophy and interstitial fibrosis (40%), mild arteriosclerosis, and moderate hyaline arteriolosclerosis

(7) Monoclonal Ig GN

Primary diagnosis: monoclonal Ig GN

Pattern of injury: membranoproliferative GN with intracapillary hyaline thrombi (pseudothrombi)

Additional features: IgM κ-staining of glomerular intracapillary deposits consistent with type 1 cryoglobulins (Waldenström macroglobulinemia/type 1 cryoglobulins/clinical), focal global glomerulosclerosis (30%), moderate tubular atrophy and interstitial fibrosis (40%), moderate arteriosclerosis, and moderate hyaline arteriolosclerosis

(8) C3 glomerulopathy

Primary diagnosis: C3 GN

Pattern of injury: membranoproliferative GN

Additional features: focal global glomerulosclerosis (20%), mild tubular atrophy and interstitial fibrosis (20%), mild arteriosclerosis, and moderate hyaline arteriolosclerosis

ISN/RPS, International Society of Nephrology/Renal Pathology Society; A/C, active/chronic.

^aIf MPO/PR3 titers are not known, it is acceptable to label as ANCA GN.