본 증례는 수술 전 증가되었던 혈청 CA 19-9 농도가 갑상선전절제술 후 정상화되었고, 갑상선내 다른 병리 소견이 없어서 갑상선유두암 조직이 CA 19-9 분비의 원인이었음을 알수 있는 증례이다. 이는 혈청 CA 19-9 증가의 원인으로서 밝혀진 갑상선유두암의 국내 첫 증례 보고이며, 췌장 담도 질환이 동반되지 않은 환자에서 혈청 CA 19-9 증가가 있다면 갑상선암의 가능성도 고려해야 함을 시사한다.
A 47-year-old man had elevated serum CA 19-9 after a routine health check-up. He had normal CA 19-9 levels during the preceding 8 years on annual heath checks. Imaging studies for pancreatic or biliary tract diseases revealed no abnormalities. A huge hypermetablic lesion was found in the right lobe of the thyroid on 18F-fluorodeoxyglucose positron emission tomography/computed tomography. We performed a fine needle aspiration of the thyroid nodule. He was diagnosed with papillary thyroid carcinoma and underwent a total thyroidectomy with a modified radical neck dissection. Serum CA 19-9 level decreased to the normal range after surgery. Although there have been few reports of patients with elevated serum CA 19-9 levels due to papillary thyroid carcinoma, this is the first report showing such an association in Korea. Thyroid cancer should be considered when the causes of elevated serum CA 19-9 are unclear. (Korean J Med 2013;84:111-115)