title: A carcinoembryonic antigen-secreting adenocarcinoma arising in tailgut cyst: clinical implications of carcinoembryonic antigen.
abstract: Tailgut cysts (TGCs) are rare congenital cysts that occur in the retrorectal or presacral spaces. Although most tailgut cysts have been reported as benign, there have been at least 9 cases associated with malignant change. We report herein on an unusual case of a 40-year-old woman with a carcinoembryonic antigen (CEA)-producing adenocarcinoma arising within a TGC who underwent surgical resection and local radiation therapy. Despite the complete resection, metastatic adenocarcinoma developed five months after surgery. CEA-producing adenocarcinoma from a TGC is extremely rare and only two cases, including this case, have been reported in the English medical literature. Besides CEA, the serum levels of CA 19-9 became markedly elevated in this patient. Given that the serum CEA level decreased to the normal range after complete resection of tumor and that the tumor recurrence was associated with a rebound of the CEA serum level, our case shows that serial measurements of serum CEA can be used for treatment planning and for assessing the patient's treatment response for this rare disease.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, 134 Shinchon- dong, Seodaemun- gu, Seoul 120-752, Korea.
authors.forename: Byoung Chul
authors.initials: BC
authors.lastname: Cho
authors.forename: Nam Kyu
authors.initials: NK
authors.lastname: Kim
authors.forename: Beom Jin
authors.initials: BJ
authors.lastname: Lim
authors.forename: Sang Ook
authors.initials: SO
authors.lastname: Kang
authors.forename: Ju Hyuk
authors.initials: JH
authors.lastname: Sohn
authors.forename: Jae Kyung
authors.initials: JK
authors.lastname: Roh
authors.forename: Sang Tae
authors.initials: ST
authors.lastname: Choi
authors.forename: Sung Ai
authors.initials: SA
authors.lastname: Kim
authors.forename: Se Eun
authors.initials: SE
authors.lastname: Park
mesh_terms: D000230:Adenocarcinoma / Q000097:blood / Q000473:pathology / Q000628:therapy*; D000328:Adult; D018395:CA-19-9 Antigen / Q000097:blood; D002272:Carcinoembryonic Antigen / Q000097:blood*; D003560:Cysts / Q000097:blood / Q000473:pathology / Q000628:therapy*; D005260:Female; D006222:Hamartoma / Q000097:blood / Q000473:pathology / Q000628:therapy*; D006801:Humans; D012004:Rectal Neoplasms / Q000097:blood / Q000473:pathology / Q000628:therapy*; D012445:Sacrococcygeal Region
chemical_list: D018395:CA-19-9 Antigen; D002272:Carcinoembryonic Antigen