Progressive Massive Fibrosis (PMF) in coal miners' pneumoconiosis is distinguished from simple CWP primarily by:

• A Bilateral masses greater than 1 cm in longest diameter (ILO category B or C large opacities) ✓
• B Presence of p-type (rounded) opacities less than 1.5 mm on chest X-ray
• C Spirometric evidence of obstructive pattern with FEV1/FVC < 0.70
• D Positive Kveim-Siltzbach test differentiating from sarcoidosis

Explanation

Progressive Massive Fibrosis (PMF) = complicated coal workers' pneumoconiosis (CWP) — characterized by large opacities (ILO classification category A ≥1cm, B > 1 cm and < 1/3 hemithorax, C > 1/3 hemithorax) on a background of simple CWP nodules. Simple CWP shows only small rounded opacities (p, q, r types < 10 mm). PMF progresses even after dust exposure cessation, causes significant functional impairment, may cavitate (secondary infection/Caplan syndrome with RA), and is associated with shortened life expectancy. Spirometry in CWP typically shows a mixed restrictive-obstructive pattern, not purely obstructive.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.