Increased risk of lung cancer in patients with chondromatous hamartoma.

Fifty-two patients with chondromatous hamartoma of the lung (CHL) operated upon in one medical center in Israel during the years 1960 to 1975 were followed through the end of 1976 for occurrence of malignancy. In 51 patients, the operation followed the finding of a coin lesion in a routine chest x-ray film (32 cases) or an x-ray film taken due to symptoms related to the chest (19 cases). In one case, it followed a cytologic diagnosis of bronchogenic carcinoma. Four cases of carcinoma of the lung were observed in this group, three of them 2 to 10 years after the CHL was first observed; in the fourth the CHL was found during an operation for lung cancer. All four lung cancers were located in the same lobe as and in proximity to the CHL. Since hamartomas were randomly distributed among the lobes, this spatial association is highly significant (p = 0.0016). The risk of lung cancer in CHL patients was estimated to be 6.3 times higher than the age-sex-ethnic adjusted rate expected for the general Israeli population. No increased risk for malignancies of other sites was found.