Primary pulmonary mucinous (colloid) adenocarcinoma.

We report a rare case of primary pulmonary mucinous (colloid) adenocarcinoma (MC) in a 79-year-old man. A computed tomographic scan of the chest showed a round, well-defined nodule in his right upper lobe that enlarged slowly over 12 months from 1.7 cm to 2.0 cm. Wedge resection of the right upper lobe was performed to obtain a definitive diagnosis by video-assisted thoracoscopic surgery. Macroscopically, the cut surface showed that the nodule was well demarcated and filled with a yellowish-white gelatinous substance. The postoperative histological diagnosis was primary pulmonary MC.