A factory worker exposed to crystalline silica dust for 20 years develops progressive dyspnea and bilateral upper-lobe nodular shadows on chest X-ray. He continues working. Which specific form of pneumoconiosis does he most likely have?
- A Byssinosis
- B Simple silicosis
- C Progressive Massive Fibrosis (PMF) — complicated silicosis ✓
- D Asbestosis
Correct answer: C. Progressive Massive Fibrosis (PMF) — complicated silicosis
Explanation
Progressive Massive Fibrosis (PMF) or complicated silicosis occurs when simple silicosis progresses with coalescence of silicotic nodules into large (>1 cm) fibrotic masses, typically in upper lobes. Continued exposure worsens fibrosis even after exposure ceases. PMF is associated with markedly reduced lung function and poor prognosis. Simple silicosis shows bilateral nodular shadows <1 cm; asbestosis causes lower-lobe fibrosis with pleural plaques; byssinosis is from cotton dust.
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.