Lung adenocarcinoma presented with reticular pattern in which both CA19-9 and carcinoembryonic antigen( CEA) were recognized as markers

A 79-year-old male whose chest X-ray revealed a localized reticular shadow in health check was once treated medically with a diagnosis of interstitial pneumonia. Regardless of the treatment, the shadow increased in its size. Positron emission tomography (PET)-computed tomography(CT) was suggestive of a primary lung cancer in clinical stage IIIA. CA19-9 and CEA were 3,568.5 U/ml and 178.2 ng/ml respectively, and a left lower lobectomy was performed. The postoperative course was uneventful. Both tumor markers declined shortly after the surgery. But they increased in 8 months after the surgery associated with tumor recurrence. In spite of chemotherapy, the patient was expired 15 months following the surgery. Immunohistochemical staining showed the tumor was a well differentiated adenocarcinoma with positive findings of both CEA and CA19-9.