A 63-year-old shipyard worker presents with a year of progressive left-sided chest pain and breathlessness. CT shows circumferential nodular pleural thickening up to 2 cm encasing the left lung with volume loss of the hemithorax, and a large ipsilateral effusion. Pleural biopsy shows epithelioid malignant cells staining positive for calretinin and WT1. Which exposure is the established causative agent?

• A Silica dust
• B Beryllium fume
• C Coal mine dust
• D Asbestos fibre ✓

Explanation

Malignant mesothelioma presents decades (typically 30 to 40 years) after asbestos exposure with rind-like unilateral pleural thickening, hemithoracic volume loss, and an effusion. Immunopositivity for calretinin, WT1, and cytokeratin 5/6 distinguishes epithelioid mesothelioma from metastatic adenocarcinoma. Silica causes silicosis with increased lung cancer risk but not mesothelioma, coal dust causes coal workers pneumoconiosis, and beryllium produces chronic beryllium disease resembling sarcoidosis.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.