Carcinoma Complicating Cyst of Lung

Cystic disease of the lung has been indicted by various writers as a precursor of carcinoma but only rarely has it been possible to prove the indictment reasonably valid. Complications of cystic disease of the lung are infection, enlargement of the cyst with compression of lung tissue, spontaneous pneumothorax, hemoptysis, perhaps bronchopleural fistula, and possibly carcinoma. Womach and Graham’ studied nine cases, operated on for congenital cystic disease, with particular reference to epithelial overgrowth at the site of the congenital malformations. In three of the cases there was evidence of such overgrowth, mainly masses of poorly differentiated epithelial cells tending to appear as spindle or cuboidal cells with a tendency toward invasion, but without evidence of metastasis. Though the process represented abnormal cellular growth, they did not feel justified in considering it malignant clinically. Graham2 cites an article by Schwyter in which the relationship of congenital malformations of the lung to tumor of the lung is discussed, with eight illustrative cases, five of whom had cysts of the lung. Murphy,3 discussing congenital cystic disease of the lung, states that at times the epithelium is cuboidal and that squamous metaplasia may be present. Under such conditions squamous cell carcinoma has been known to occur. Bass and Singer4 reported a patient with cystic disease of the lung, who had emphysema and secondary abscess formation preceding the development of a diffuse adenocarcinoma in the same lung. Koral5 studied 100 cases with cystic and bullous emphysema of the lungs and found seven cases with cystic emphysema who developed bronchial carcinoma, but he did not mention their relation to the cystic areas. No case of bullous emphysema, however, developed bronchial carcinoma. Moersch and Clagett6 reported two with malignancy among 44 cases of pulmonary cystic disease. One was a 22 year old female in whom a bronchogenic cyst removed from the mediastinum showed an adencarcinoma, Grade III, arising in its wall. The other was a 36 year old male who had a cyst removed from the left thorax. In the region of the cyst wall opposite the pericardium, was a mass of soft tissue which on biopsy showed squamous cell carcinoma, Grade IV. Rogers7 in studying the question of predisposition to pulmonary neoplasms in patients with cystic disease of the lung, states that the likelihood based on available statistical data seems remote. He found only two malignancies among persons with cystic disease, one a small adenocarcinoma discovered in the surgical specimen of a patient operated on for existing cystic bronchiectasis, the second, a rapidly fatal malignancy in the upper lobe in one with bilateral cystic disease. At the (Kennedy) Veterans Administration Medical Teaching Group From the Pulmonary Disease Section, Medical Service, Veterans Administration