Intralobar pulmonary sequestration presenting increased serum CA19-9 and CA125

A 39-year-old man was admitted to our hospital for further evaluation of a consolidated shadow and clarification of the cause of serum tumor marker elevation (CA19-9 496.2 U/ml, CA125 160.6 U/ml). Chest computed tomography revealed a well-defined homogeneous nodule in the left S-10. Angiography showed one aberrant artery, branching from the ascending aorta. Intralobar pulmonary sequestration was diagnosed and the sequestrated lung was resected. Microscopic findings of the sequestrated lung showed a mucus-containing cystically dilated bronchus, which was covered with ciliated cylindrical epithelium. Immunohistochemical staining showed positive staining for CA19-9 and CA125 in both the ciliated cylindrical epithelium and mucus. Serum values of tumor markers returned to their normal range after surgery.