Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Lung Cancer associated with Asbestos Exposure
- Radiologic Findings
- Chest radiograph shows mass shadow at right hilum. Ill-defined areas of increased opacity are seen along the bilateral pleural surfaces. Chest CT scan revealed mass occluding the segmental branch of right upper lobar bronchus and multiple pleural based opacity in both hemithoaces without calcification.
Right pneumonectomy was done. Pathologic examination revealed squamous cell carcinoma in right upper lobe and multiple fibrotic masses along the pleural surface, consistent with asbesos related pleural plaque. There was no definite evidence of parenchymal asbestosis.
He is a heavy smoker (40 pack year) and worked at chemical texture company for 11 years (1968-1978).
- Brief Review
- The fact that asbestos exposure is associated with malignancies, especially mesothelioma and lung cancer, has been long recognized by experiments in animals, and studies in humans suggest a close relationship between asbestosis and lung cancer. Asbestos exerts a carcinogenic effect even in the abscence of smoking, whereas it acts synergistically when both risk factors are present (1). The latent period is variable. Some cases occur 5 to 9 years after the onset of exposure, but the risk rises until at least 30 years after first exposure (2).
Lung cancer in asbestos workers arised principally in the main bronchi and occurs in all the common histologic forms, including squamous cell, small cell, adenocarcinoma, and large cell carcinoma. It can also aris in the smaller bronchi and in the peripheral part of the lung (3).
Increased lung markings are present radiologically more often in asbestos workers with lung cancer in whom lung biopsy reveals fibrosis, although random biopsy specimens may miss it. Nevertheless, it has been shown that asbestos is associated with lung cancer even in the absence of radiologically apparent pulmonary fibrosis.
- References
- 1. Lee BW, et al. Association of cigarette smoking and asbestos exposure with location and histology of lung cancer. Am J Respir Crit Care Med 1998; 157: 748-755.
2. Sarraci R. Asbestos and lung cancer: an analysis of the epidemiological evidence on the asbestos-smoking interaction. Int J Cancer 1977; 20: 323.
3. Talcott JA, et al. Asbestos-related malignancy. Curr Probl Cancer 1988; 12: 138-177.
- Keywords
- Lung, Pleura, Malignant tumor, Occupational lung disease,