BRIEF COMMUNICATION Elevated carbohydrate antigen 19-9 in a dermoid cyst C. Atabekog ˘lu, E.A. BozacV * , S. Tezcan Ankara University Faculty of Medicine Department of Obstetrics and Gynecology, Ankara, Turkey Received 23 June 2005; received in revised form 21 July 2005; accepted 26 July 2005 Serum carbohydrate antigen CA 19-9 was initially described in gastrointestinal adenocarcinomas. However, its specificity extends to any tissue malignancy. A 25-year-old virgin woman was referred to this clinic because of a very large and complicated right ovarian cyst detected by abdominal ultrasonogra- phy. Abdominopelvic ultrasonography and comput- erized tomography revealed a lobulated cystic lesion measuring 30 cm and containing heteroge- neous solid structures as well as papillary projec- tions. The left ovary and other intra-abdominal structures were normal. Serum CA 19-9 level was 1430 U/mL and CA 125 level was 46.6 U/mL. Other tumor markers were in normal ranges. Any gastro- intestinal system disease was ruled out by imaging and endoscopic procedures. Right salpingo-oophorectomy was performed, and a histopathologic evaluation of a frozen section determined the lesion to be a dermoid cyst. Multiple sections from various cyst sites did not reveal any malignant foci. Some cystic cavities were lined with simple mucinous epithelium, and with respiratory mucosa that expressed diffuse and strong cytoplasmic positivity for CA 19-9 (Fig. 1). Therefore, the mature teratoma itself was identi- fied immunohistochemically as the source of CA- 19-9. Postoperatively, CA 19-9 and CA 125 levels returned to normal. In 1% of dermoid cysts, one tissue element shows malignant transformation, most often to squamous cell carcinoma. Elevated serum CA 125 and CA 19-9 levels seem unrelated to malignant transformation [1]. Increased CA 19-9 levels in some dermoid ovarian cysts and dermoid cysts in many other locations have been reported [2—5], but the present study is probably reporting the highest serum level of CA 19-9 in association with a dermoid cyst — of the ovary or any other location — in English literature. Immunohistochemically, CA 19-9 staining was prominent on the apical cyto- 0020-7292/$ - see front matter D 2005 International Federation of Gynecology and Obstetrics. Published by Ireland Ltd. All rights reserved. doi:10.1016/j.ijgo.2005.07.019 * Corresponding author. Tel.: +90 533 411 4033; fax: +90 312 320 35 53. E-mail address: eclamptic2000@yahoo.com (E.A. BozacV). KEYWORDS Carbohydrate antigen CA 19-9; Tumor markers; Dermoid cyst; Mature cystic teratoma International Journal of Gynecology and Obstetrics (2005) 91, 262 — 263 www.elsevier.com/locate/ijgo