Ciliated muconodular papillary tumor of the lung: report of five cases.

We report five serial cases of ciliated muconodular papillary tumor (CMPT) of the lung. CMPT is characterized as a low-grade malignant tumor with ciliated columnar epithelial cells combined with goblet cells, typically presenting as peripheral lung tumor and often causing diagnostic or therapeutic problems. In the cases described here, all patients presented with abnormal chest shadow but no definitive symptoms. Although all tumors were peripheral, computed tomography (CT) revealed various radiographic findings including small lung nodules, ground-grass opacity or irregular-shaped consolidation. All patients underwent complete surgical resection, and no recurrence has been noted over follow-up. In all cases, pathological findings included columnar ciliated cells with mucus lakes, consistent with the immunohistochemical staining. As there are few reports on this tumor entity, which has not yet received a WHO classification, we believe our case series may be of interest.