Extramammary Paget's disease of the bronchial epithelium. We report the first case, to our knowledge, of extramammary Paget's disease of the bronchial epithelium. The tumor displayed Paget's cells scattered within the bronchial epithelium in most of the lesion, but infiltrating into the bronchial submucosa and pulmonary parenchyma with microglandular and papillary patterns in some area. In addition to the histologic findings of coexistence with adenocarcinomatous components, in situ involvement into bronchial glands and ducts by Paget's cells was observed, suggesting that extramammary Paget's disease of the bronchial epithelium may be a variant of pulmonary adenocarcinoma, which is associated with bronchial glands. 