Primary Pulmonary Mucinous (Colloid) Adenocarcinoma with Postoperative Bone Metastasis

We describe rare primary pulmonary mucinous (colloid) adenocarcinoma in an 80-year-old man. Chest computed tomography revealed a lobulated, well-defined nodule with a diameter of 3.2 cm in the right middle lobe. Transbronchial biopsy via endobronchial ultrasound with a guide sheath did not uncover malignancy. Right middle lobectomy proceeded because the tumor was located close to the pulmonary hilum. Macroscopically, the cut surface of the nodule comprised a well demarcated area of somewhat transparent granular aggregates and a yellow-white gelatinous substance. Computed tomography findings of a solitary metastatic lesion in the left fifth costal head 28 months thereafter were consistent with those of a mucin-rich tumor, which was effectively treated by radiotherapy.