Ciliated muconodular papillary tumor of the lung: a case report and literature review.

Ciliated muconodular papillary tumor (CMPT) of the lung is characterized as a peripheral low-grade malignant tumor with ciliated columnar cells and goblet cells with basaloid cell proliferation. Herein, we report on a case of CMPT with a radiologically abnormal shadow which was reminiscent of adenocarcinoma. The patient underwent right S6 + S8a segmentectomy because an intraoperative biopsy suggested CMPT, the malignancy of which was difficult to distinguish; however, the tumor was small and located in the peripheral lung. Many details of this tumor remain unclear, as CMPT is a rare tumor with few reports. CMPT has therefore not yet been classified by the WHO. In this report, we will consider the characteristics of CMPT and treatment based on our case and previous case reports.