CURRENT INTEREST in the management of isolated solid circumscribed densities (1) within the lung parenchyma (pulmonary “coin” lesions), usually found on routine examination, prompts us to report our experiences with a group of such lesions within which calcification was demonstrated roentg enographically. Thirteen such cases have been found among a large number of pulmonary coin lesions gathered, for the most part, from the chest clinics under the direction of the Bureau of Tuberculosis, Department of Health, New York City. Observations In 5 cases, the coin lesion was excised. Two lesions showed coneentric growth over a period of several years. Both patients at first rejected the idea of operative intervention but finally agreed to it after much persuasion. The outstanding features of this group are outlined in Table I. None of the 5 lesions was malignant. In the remaining 8 patients, the pulmonary coin lesions were observed to remain unchanged for periods varying from two to twelve years. The pertinent facts concerning this group are outlined in Table II. None of the patients developed signs or symptoms of malignant disease. All 13 patients were asymptomatic. Eight patients were over forty years of age. Twelve were males. Discussion Our observations lend support to the opinion, already expressed by others, that the demonstration of calcification within a coin lesion may be considered as strong evidence that the lesion is not malignant (2). It follows, therefore, that the generally accepted policy of routine excision of solid circumscribed pulmonary lesions (3) should not be applied to coin lesions with calcification. While we are well aware of rare cases of calcification within malignant lung tumors, such as bronchogenic carcinoma enveloping a calcified tuberculous focus or some forms of sarcoma, we feel that these exceptions do not warrant the routine removal of coin lesions with demonstrable calcification. For this reason, one should make every effort to detect the presence of calcification in all coin lesions, using sectional radiography routinely. By this means information is easily obtainable which may justify periodic supervision rather than immediate excision of accidentally discovered coin lesions in patients who represent increased operative risks. Summary In 13 cases of pulmonary coin lesions with calcification no evidence of malignant growth was demonstrated either by operation (5 cases) or by prolonged observation (8 cases). Tomographic examination of every coin lesion is advised, since the demonstration of calcium is strongly indicative of non-malignant disease. Such information may be of considerable assistance when one must weigh the risk of operation against the hazard of periodic observation in the management of the individual case. Acknowledgment: We express our appreciation to Mr. Valentin Gill for the preparation of the photographic material. We are grateful, also, to the many physicians and the members of the staffs of hospitals in New York City who assisted us in obtaining follow-up reports.