Double or nothing: old chest X-ray as a clue to lung mass.

Mucoepidermoid carcinoma is ayoung person's lung cancer with no apparent causal connection to smoking. It exhibits slow growth, which can make it challenging to detect changes in size on serial chest imaging. Another way of describing its growth pattern is that mucoepidermoid carcinoma has an unusually long volume doubling time. We describe acase of an incidental lung nodule diagnosed as mucoepidermoid carcinoma in which aprior chest radiograph provided aclue to the indolent nature of the abnormality and therefore argued against typical lung cancer. In the same context, we underscore the value of volumetric analy-sis in improving the accuracy of nodule growth determinations, which further strengthens the argument that the importance of locating prior imaging has not diminished in contemporary pulmonary practice.