대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Lung Cancer associated with Pneumoconiosis

Radiologic Findings

PA and lateral radiographs show numerous and even sized nodular opacities predominently in both upper and middle lung zones and also show a large mass in the left retocardiac area. Conventional and high-resolution CT scan demonstrate: 1) a large heterogeous attenuated mass in the left lower lobe, 2) numerous discrete small nodules mainly in both upper lungs, prodominantly in centrilobular and subpleural location.

Pneumoconiosis with lung cancer was diagnosed based on history of exposure to coal dust for 30 years, radiologic findings, and fine-needle aspiration cytology for the mass in left lower lobe.

Brief Review

Lung cancer occurs slightly less frequently in coal miners than in comparable populations (1). Difficulties may arise in distinguishing bronchiogenic carcinoma from early PMF or, less frequently, Caplan's syndrome. In such situations, inspection of serial chest radiographs, which are usually available in coal workers, may be helpful. Carcinomas are generally better defined and more rapidly growing than early massive fibrosis. In such instances, CT may add additional diagnostic information (2). Topography of parenchymal abnormalities and analysis of associated lesions on CT represent important data in the differential diagnosis. Although conglomerations can be observed in all areas of the lungs, PMF is found mainly in the posterior segment of the upper lobes or in the superior segment of the lower lobes, usually on a background of simple pneumoconiosis. With a low suspicion of malignancy, a second CT study may be performed several weeks later, using a similar technical protocol to that initially performed, to detect any change in size that would strongly suggest carcinoma (2). Lung cancers frequently occurred with simple pneumoconiosis compared with complicated pneumoconiosis with massive fibrosis, a difference that was highly significant (33% versus 12%). The histology of the pneumoconiosis-related lung cancers showed squamous cell carcinomas (SCCs) (57%), adenocarcinomas (33%), small cell carcinomas (5%), large cell carcinomas (2%) (3). SCCs arising from patients with pneumoconiosis had a significantly higher frequency of the peripheral type than SCCs from patients without pneumoconiosis. Moreover, peripheral-type SCCs accounted for 43% of the pneumoconiosis-related lung cancers, which indicated an absolutely increased number of peripheral-type SCCs, as compared with those from patients without pneumoconiosis (43% versus 18%) (3). Diffuse interstitial -type pneumoconiosis is highly predisposed to lung cancer, especially peripheral-type SCCs of the lung (3).

References

1. Costello J, Ortmeyer CE, Morgan WKC. Mortality for lung cancer in US coal miners. American Journal of Public health. 1974;64:222-224.
2. Remy-Jardin M, Remy J, Farre I, Marquette HC. Computed tomographic evaluation of silicosis and coal workers pneumoconiosis. The Radiologic Clinics of Northamerica. 1992;30(6):1155-1176.
3. Katabami M, Akita HD, Honma K, Saitoh Y, et, al. Pneumoconiosis-related lung cancers: preferential occurrence from diffuse interstitial fibrosis-type pneumoconiosis. American Journal of Respiratory and Critical Care Medicine. 2000;162(1):295-300

Keywords

Lung, Malignant tumor, Occupational lung disease,