A 70-year-old non-smoker woman has HRCT showing bilateral basilar-predominant subpleural reticular opacities with honeycombing. Surgical biopsy shows temporal and spatial heterogeneity with fibroblastic foci, dense fibrosis, and honeycomb change adjacent to normal lung. This histological pattern is:
- A Non-specific interstitial pneumonia (NSIP)
- B Cryptogenic organizing pneumonia (COP)
- C Usual interstitial pneumonia (UIP) ✓
- D Desquamative interstitial pneumonia (DIP)
Correct answer: C. Usual interstitial pneumonia (UIP)
Explanation
UIP (usual interstitial pneumonia) is the histological pattern of idiopathic pulmonary fibrosis, characterized by spatial and temporal heterogeneity, dense subpleural fibrosis, fibroblastic foci (the 'active frontier'), and honeycombing. NSIP shows uniform fibrosis without honeycombing; COP shows buds of granulation tissue in alveoli (Masson bodies); DIP shows diffuse macrophage accumulation in alveolar spaces.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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