[A pathological study of carcinoma of the lung and pneumoconiosis]

Pathological studies on lung carcinoma associated with pneumoconiosis were made in order to clarify the etiological significance of pneumoconiosis in carcinoma of the lung. Between 1960 and 1986, the author evaluated approximately 450 autopsies of pneumoconiosis. Of these, 150 were consecutive autopsies in our over laboratory and the remaining 300 were kindly provided by other hospitals. Carcinoma of the lung was seen in 48 of the autopsies. Pathological studies determine histologic type, cancer site, and severity of pneumoconiosis were performed in the 48 cases. The severity of pneumoconiosis was determined by the extent of progressive massive fibrosis (PMF). Simple pneumoconiosis was classified as mild, pneumoconiosis with PMF smaller than segmental region as moderate and pneumoconiosis with PMF larger than lung segment as severe. Carcinoma of the lung was seen in 25 of our own consecutive autopsies, an incidence of 17.9%. The incidence of lung carcinoma was high among cases of mild pneumoconiosis and low among cases of severe pneumoconiosis. Overall, the predominant cancer was squamous cell carcinoma (54.2%) followed by small-cell carcinoma (22.9%) and adenocarcinoma (14.6%). There was a clear trend that most of the squamous cell carcinomas were found in the larger airways, whereas the adenocarcinoma was found only in the peripheral lung tissues. In cases of mild pneumoconiosis, the majority of tumors arose in the right, upper and larger airways. On the other hand, in cases of moderate and severe pneumoconiosis, more tumors arose in the left, lower and peripheral lung areas.(ABSTRACT TRUNCATED AT 250 WORDS)