Step 5 of 9 · Core Curriculum

Active vs Chronic Lesions

A required learning step before pattern recognition. Classify each finding as active, chronic, or mixed — and explain the visual evidence.

Learner prompt

“Is this lesion potentially reversible, chronic/scarring, or mixed?”

Active

  • Hypercellularity
  • Necrosis
  • Cellular crescents
  • Endocapillary proliferation
  • Active interstitial inflammation
  • Tubulitis
  • Edema
  • Thrombosis
  • Vasculitis

Chronic

  • Global or segmental sclerosis
  • Fibrous crescents
  • GBM thickening or duplication
  • Interstitial fibrosis
  • Tubular atrophy
  • Vascular medial thickening
  • Intimal fibrosis
  • Arteriolar hyalinosis

Mixed

  • Fibrocellular crescents
  • Active inflammation superimposed on chronic scarring
  • Chronic lesions with active injury

Assessment items

  • Classify lesion as active, chronic, or mixed.
  • Explain the visual evidence.
  • Link active/chronic classification to clinical reasoning and prognosis.