A 45-year-old woman with rheumatoid arthritis develops progressive exertional dyspnea. HRCT shows bilateral basal-predominant reticular opacities with honeycombing and traction bronchiectasis. Biopsy reveals temporal heterogeneity with fibroblastic foci and subpleural honeycombing. This pattern is called:
- A Nonspecific interstitial pneumonia (NSIP)
- B Usual interstitial pneumonia (UIP) ✓
- C Organizing pneumonia (OP)
- D Lymphoid interstitial pneumonia (LIP)
Correct answer: B. Usual interstitial pneumonia (UIP)
Explanation
Usual interstitial pneumonia (UIP) is the histological pattern underlying idiopathic pulmonary fibrosis and can occur in connective tissue diseases like RA. Its hallmarks are temporal heterogeneity (areas of normal lung alternating with fibrosis and honeycombing), fibroblastic foci at the advancing edge, and subpleural/basal distribution. NSIP, in contrast, shows temporal homogeneity with diffuse interstitial fibrosis and inflammation without honeycombing, carrying a better prognosis.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.