Columbia Classification of FSGS (Biopsy Variant)
The Columbia classification of focal segmental glomerulosclerosis (D'Agati and colleagues 2004).
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- At least one glomerulus with segmental or global collapse AND overlying…
- No
- At least one segmental lesion in the tip domain
- No
- Any perihilar sclerosis anywhere in the biopsy?
- No
- At least one glomerulus with segmental endocapillary hypercellularity…
- No
- Perihilar hyalinosis or sclerosis in MORE THAN 50 percent of the glomeruli…
- No
- At least one glomerulus with a segmental increase in matrix obliterating the…
- Yes
Result: Columbia Not otherwise specified (NOS) variant.
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What the result means
- Collapsing
- Segmental or global collapse with overlying podocyte hypertrophy and hyperplasia. No exclusions: it takes precedence over everything.
- Tip
- A segmental lesion in the tip domain with the tubular pole identified. Vetoed by ANY perihilar sclerosis in the biopsy.
- Cellular
- Segmental endocapillary hypercellularity occluding lumina. Requires tip and collapsing to be excluded.
- Perihilar
- Perihilar hyalinosis or sclerosis in more than half the glomeruli bearing segmental lesions.
- NOS
- A segmental increase in matrix obliterating capillary lumina. A diagnosis of exclusion.
- Scope
- Names a morphologic variant. It does not diagnose FSGS and does not distinguish primary from secondary disease.
What you enter
- At least one glomerulus with segmental or global collapse AND overlying podocyte hypertrophy and hyperplasia?
- At least one segmental lesion in the tip domain, with the tubular pole identified and an adhesion or confluence of podocytes with parietal or tubular cells?
- Any perihilar sclerosis anywhere in the biopsy?
- At least one glomerulus with segmental endocapillary hypercellularity occluding lumina, with or without foam cells and karyorrhexis?
- Perihilar hyalinosis or sclerosis in MORE THAN 50 percent of the glomeruli that bear segmental lesions?
- At least one glomerulus with a segmental increase in matrix obliterating the capillary lumina?
Full field descriptions
- At least one glomerulus with segmental or global collapse AND overlying podocyte hypertrophy and hyperplasia? Defines the collapsing variant, which takes precedence over every other finding.
- At least one segmental lesion in the tip domain, with the tubular pole identified and an adhesion or confluence of podocytes with parietal or tubular cells? The tip domain is the outer 25 percent of the tuft next to the origin of the proximal tubule. The lesion may be cellular or sclerosing.
- Any perihilar sclerosis anywhere in the biopsy? This VETOES the tip variant even when a qualifying tip lesion is present. It is not a ranking, it is an exclusion written into the tip definition.
- At least one glomerulus with segmental endocapillary hypercellularity occluding lumina, with or without foam cells and karyorrhexis? Defines the cellular variant. Several references add a threshold of at least 25 percent of the tuft; that qualifier is narrative rather than part of the criteria table, so it is not enforced here.
- Perihilar hyalinosis or sclerosis in MORE THAN 50 percent of the glomeruli that bear segmental lesions? Required for the perihilar variant, in addition to at least one glomerulus with perihilar hyalinosis. Strictly more than half, so exactly 50 percent does not qualify.
- At least one glomerulus with a segmental increase in matrix obliterating the capillary lumina? Defines the not-otherwise-specified variant, which is a diagnosis of exclusion. May include segmental capillary collapse WITHOUT overlying podocyte hyperplasia.
How this is calculated
D'Agati VD, Fogo AB, Bruijn JA, Jennette JC. Pathologic classification of focal segmental glomerulosclerosis: a working proposal. Am J Kidney Dis. 2004;43(2):368-382. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.