Abstract
Background. Primary lung cancer associated with an elevated CA19-9 level is extremely rare. Case 1. A 67-year-old woman complaining of a cough and back pain was referred to our hospital. Chest CT revealed a mass in the lower lobe of the right lung. The CEA and CA19-9 levels were 29.51 ng/ml and 6340 U/ml, respectively, and bronchoscopic cytology showed adenocarcinoma. We therefore diagnosed the patient with lung cancer and performed right middle and lower lobectomy with lymph node dissection after chemotherapy. The postoperative diagnosis was mucinous bronchioloalveolar carcinoma with mediastinal lymph node metastasis (T3N2M0 stage IIIA). Adjuvant chemotherapy was administered after the operation, and the CA19-9 level decreased to 129 ng/ml. However, the patient developed recurrence four months after surgery, and the CA19-9 level again became elevated. Case 2. A 78-year-old woman was referred to our hospital due to an abnormal shadow on an X-ray film. The CEA and CA19-9 levels were 75.58 ng/ml and 1622 U/ml, respectively, and chest CT revealed a nodule in S5 of the left lung. We thus diagnosed the patient with lung cancer and subsequently performed surgery. A diagnosis of adenocarcinoma was made based on the findings of an intraoperative pathological study, and left upper lobectomy with lymph node dissection was performed. The postoperative diagnosis was mixed adenocarcinoma with mediastinal lymph node metastasis (T3N2M0 stage IIIA). The CA19-9 level decreased to 889 U/ml after the operation. Conclusions. Elevation of the CA19-9 level reflects the condition of patients with lung cancer and has the potential to be a useful marker of recurrence and the response to treatment.
