Diagnostic pitfalls beyond progressive massive fibrosis: a narrative review with illustrative cases from occupational lung disease practice

Background Pneumoconiosis, particularly when complicated by progressive massive fibrosis (PMF), is characterised by complex radiological patterns that may overlap with malignancy, infection, and vascular disease. Such overlap frequently generates diagnostic uncertainty and may lead to delayed recognition of coexisting conditions or inappropriate management strategies. Despite these challenges, the literature remains largely fragmented and dominated by isolated case reports. Objective This narrative review aims to synthesise current evidence on diagnostic pitfalls encountered in pneumoconiosis and to illustrate recurrent clinical and radiological challenges through selected cases from occupational lung disease practice. Methods A structured review of the literature was undertaken focusing on malignancy, infectious complications, and thromboembolic disease in the setting of pneumoconiosis and PMF. To contextualise these findings, representative illustrative cases from real-world occupational medicine practice are integrated to highlight common diagnostic patterns and sources of misclassification. Key findings Mass-like opacities, cavitary lesions, vertebral involvement, and increased metabolic activity on FDG–PET imaging may occur in both benign fibrotic progression and serious coexisting conditions. Lung cancer, lymphoma, tuberculosis (including extrapulmonary forms), fungal colonisation, and pulmonary thromboembolism may closely mimic PMF progression. Radiological features such as cavitation or FDG uptake lack sufficient specificity when interpreted in isolation. Conclusion PMF should not be regarded as a comprehensive explanation for new or evolving radiological findings in patients with pneumoconiosis. A multidisciplinary approach integrating longitudinal imaging, advanced radiological techniques, and targeted tissue sampling is essential to avoid diagnostic oversimplification and to optimise clinical decision-making in occupational lung disease.