Document 66NYdbvRjmaNDRM8jmnZdZBg

ASBESTOS 217 The discrepancy between the two incidences in Switzerland is of the same order as that found in the smaller series by Lynch and Cannon In the United States. Suggestive as these and other data are, Stoll, Bass and Angrist (1951) were dissatisfied with the statistical woight ono could put upon available figures at that time which included, in addition to those of Lynch and Cannon, a series of 235 cases of asbesiosis with 31 carcinomas of the lung (13-2 per cent) which is again almost identical with Ihe finding of Behrens. They refer also to another series of 115 cases with 14*8 per cent lung tumours. Describing the case of a worker who had been engaged for only 6 years covering pipes with asbestos and who had refused to take precautions by wearing a respirator, they point out that except for weakness and persistent cough nothing noteworthy was found unlil malignant cells were found in the bone marrow. Radiographs of the chest showed numerous large discrete oval shadows which were interpreted rather as metastatic deposits than primary tumours. Post-mortom examination showed asbesiosis with scattered large nodules and metastases in kidneys, brain and liver. Histo logical examination confirmed the presence of asbesiosis bodies and ana plastic carcinoma of the lung, with numerous metastases. There appeared to be some doubt about the primary focus of malignancy in this case, and the authors inclined toward a multiple origin. Whethor this case is relevant to the problem of asbBStosis cancer is open to question, but the authors were led to suggest that asbestos must itself be regarded as a direct carcinogen in respect of its composition as a silicate. A less compromising attitude is taken by Werber (1952) who states cate gorically that in 7 -17 per cent of cases of asbesiosis after a latent period of about 1$-20 years, as a result of epithelial metaplasia, carcinoma becomes established in the lung. Werber then reports what appears to be a clear-cut caso successfully operated on. The patient was a man of 58 years who, after years of work in asbestos with complaint of irritant cough, showed, in a mass radiographic investigation, a well-marked dense round shadow In the right lower lung field associated with bilateral finely granular shadows in the middle and lower fields, more marked on the right side. Lobectomy of the right lower lobe confirmed the presence of a non' keratinizing squamous cell carcinoma. Nearly the whole of the lower lobe was occupied by an almost certainly bronchogenic (postero-lateral segment) tumour. Asbesiosis bodies were found in the lung and in an excised hllus .lymph node. Recovery was uneventful and x-ray examination showed later * expansion of the upper and middle lobes. : A suggest!vo case is also described by Curcton (1948) of a young woman of ',37 years who 15 years before had left asbestos work after 7 years in the industry. Necropsy showed a predominantly squamous-celled bronchial carcinoma accompanied by asbestos bodies and fibrosis in both lungs. This author is cautious about the relation between the neoplasm and the asbestosis