PULMONARY CARCINOID-TUMORS - COMPARATIVE REGIONAL STUDY

Twenty-two pulmonary carcinoid tumors (18 central, 4 peripheral) were seen in this department over an 11-year period. The majority of the tumors displayed a mixed pattern on microscopic examination, and cell-nest formation was a prominent feature in sixteen. The findings are at variance with the results of a similar series reported from Japan and suggest that there is regional variation in the tumor pattern of pulmonary carcinoids. Various aspects of the histopathology are discussed, and a causal relationship between ossification of bronchial cartilage in these tumors and locally produced calcitonin is postulated.