Carcinoma Arising in a Congenital Cyst of the Lung. Report of a Case.

INTRODUCTION C ASES OF CARCINOMA ARISING IN A SOLitary congenital lung cyst are exceedingly rare if malignancies arising in lungs with chronic cystic lung disease are not considered. Womack and Graham1 first suggested the possibility of this latter coexistence in 1941 when they reported finding metaplastic masses of poorly differentiated epithelial cells lining some cysts in one-third of their nine cases of chronic cystic lung disease. They questioned that these changes might be of early carcinomatous type, since these metaplastic cells showed a tendency towards local invasion, but in no instance showed metastases. One year later, these same authors’ reported four cases to illustrate this coexistence, but it was 1955 before a report of carcinoma arising in the wall of a solitary congenital lung cyst appeared.’ Since 1955, two acceptable cases4’5 and one possible case’ of carcinoma arising in a congenital lung cyst have been reported, although many reports representing over 60 cases of the coexistence of carcinoma and chronic cystic lung disease have appeared.’ We will present an additional case of carcinoma arising in a solitary congenital lung cyst, briefly discuss this condition, and point out the dangers of assuming that a cystic lung lesion is invariably benign.