Step 4 of 9 · Core Curriculum

Compartment-Based Biopsy Interpretation

Compartment-first interpretation. Identify the primary compartment, the involved substructure, and the distribution before naming a diagnosis.

For each image, ask

  • Which compartment is most involved?
  • Which substructure is affected?
  • Is the lesion focal, diffuse, segmental, or global?
  • Is the lesion active, chronic, or mixed?
  • What pattern is emerging?

Glomerular compartment

  • Glomerular tuft
  • Capillary loops
  • Mesangium
  • Bowman's space
  • Podocytes
  • GBM
  • Crescents
  • Sclerosis

Vascular compartment

  • Arterioles
  • Interlobular arteries
  • Intima
  • Media
  • Endothelium
  • Thrombi
  • Hyalinosis
  • Vasculitis

Tubulointerstitial compartment

  • Tubules
  • Tubular basement membranes
  • Interstitium
  • Interstitial inflammation
  • Interstitial fibrosis
  • Tubular atrophy
  • Casts
  • Crystals

Mixed / multi-compartment

Many disease processes cross compartments. When that's the case, name each involved compartment and the dominant pattern in each before integrating.