PLEURAL EPIDERMOID CARCINOMA FROM DISPLACED SKIN FOLLOWING EXTRAPLEURAL PNEUMOTHORAX IN A PATIENT EXPOSED TO ASBESTOS

This report illustrates a rare case of primary epidermoid carcinoma of the pleura in a patient previously treated by artificial extrapleural pneumothorax for active tuberculosis. The patient had also been occup ationally exposed to asbestos. Light microscopic examination showed tw o different lesions: laminar pleural fragments were covered by normal squamous epithelium that was similar in all respects to epidermis, whe reas nodular fragments were composed of well-differentiated infiltrati ng carcinoma. These findings support the hypothesis that the carcinoma arose from normal epidermis seeded in the pleural cavity during multi ple air refills to maintain the pneumothorax. A possible interaction b etween asbestos fibres and chronic inflammation might have potentiated tumour development.