Incidentally Detected Colon Cancer During the Staging Workup for Lung Cancer

We read with interest the article by Jeon et al (July 2008) on esophageal and laryngeal cancer incidentally found during the staging work-up for lung cancer.1 We would like to share our experience. A 58-year-old woman presented in our institution with an abnormal chest radiograph on mass screening. She was a nonsmoker and had no history of carcinogen exposure. The plain chest radiograph and chest computed tomography (CT) scan showed a mass lesion in the right upper lobe. Transbronchial biopsy showed lung adenocarcinoma. Work-up to assess the possibility of metastasis of the disease was performed by physical examination, routine biochemistry, CT scan of the abdomen, brain magnetic resonance imaging, and bone scanning. When CT scan of the abdomen was obtained to rule out distant metastasis of lung cancer, it revealed tumor in the ascending colon. No other pathologic lesions were found. The 2 tumors were different in morphology on image studies, including CT scan and fiberscopic observation. The pathologic findings of the colon and the lung were apparently different from each other. Therefore, these lesions were diagnosed to be primary adenocarcinoma of both the colon and the lung. Because the possibility of local progression of colon cancer could not be ruled out, surgical resection of colon cancer was carried out first. Three weeks after the colon surgery, a radical lobectomy of the right lung was performed. Pathologic diagnosis of the colon tumor was moderately differentiated adenocarcinoma and that of lung mass was well-differentiated adenocarcinoma. The pathologic features of these cancers were apparently different from each other, and the probability of one being a metastasis of the other was excluded. Postoperative course was unremarkable. The patient was well with no recurrence of these cancers for 6 years. The patient developed multiple pulmonary small nodules, which were pathologically diagnosed as pulmonary metastasis of the lung adenocarcinoma. She was treated with gefitinib for more than 2 years, but she died of lung cancer 9 years after the surgical therapy for the primary lung adenocarcinoma. We report a patient in whom a colon cancer was discovered during the staging workup for lung cancer. The condition of our patient was very similar to that of the patient in the report by Jeon et al,1 and we can fully share their observations. Although colon cancer in our patient was not found by fluorodeoxyglucose positron emission tomography/CT, incidentally identified lesions should be thoroughly explored to rule out the presence of hidden malignancy and possibility of synchronous multiple primary tumors, as Jeon et al described.1