A 38-year-old foundry worker presents with progressive exertional dyspnoea. Chest X-ray shows bilateral upper lobe small rounded opacities with eggshell calcification of hilar lymph nodes. The MOST likely diagnosis and its causative dust are:
- A Silicosis; crystalline silica (SiO2) ✓
- B Asbestosis; chrysotile asbestos fibres
- C Progressive Massive Fibrosis; coal dust
- D Byssinosis; cotton dust
Explanation
Eggshell calcification of hilar/mediastinal lymph nodes is pathognomonic of silicosis. Crystalline silica (SiO2), inhaled by foundry workers, stonemasons, sandblasters, and miners, causes macrophage activation, fibrosis, and characteristic rounded opacities in upper lobes with hilar lymph node eggshell calcification. Asbestosis causes lower-lobe reticular opacities, pleural plaques, and mesothelioma — not eggshell calcification. Progressive massive fibrosis (PMF) in coal workers' pneumoconiosis produces large conglomerate opacities but not eggshell calcification. Byssinosis presents with Monday morning chest tightness and reversible airflow obstruction — not radiographic upper lobe opacities.
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.