www.kjurology.org DOI:10.4111/kju.2010.51.7.498 Case Report Alpha-Methylacyl-Coenzyme A Racemase-Expressing Urachal Adenocarcinoma of the Abdominal Wall Yun-Sok Ha, Young-Won Kim, Byung-Dal Min, Ok-Jun Lee1, Yong-June Kim, Seok-Joong Yun, Sang-Cheol Lee, Wun-Jae Kim Departments of Urology and 1Pathology, Chungbuk National University College of Medicine, Cheongju, Korea Urachal adenocarcinomas are very rare and about one third of these neoplasms arise in urachal remnants. To demonstrate the origin of the urachal adenocarcinoma is not easy, but it is very important for managing patient care. We report on a 35-year-old man who complained of a palpable mass in the periumbilical area. The mass was in- cidentally identified 10 days earlier. Computed tomography revealed a well-defined enhancing mass with internal calcification and septation abutting on the dome of the urinary bladder. The clinical diagnosis was urachal cancer, which seemed to invade the urinary bladder. Thus, we performed mass excision and partial resection of the bladder. Histopathologically, the mass was diagnosed as mucinous cystadenocarcinoma originating from urachal remnants that showed an unusual expression of alpha-meth- ylacyl-coenzyme A racemase (AMACR). To our knowledge, this report is the first case of AMACR-expressing urachal adenocarcinoma arising in the abdominal wall. Key Words: Alpha-methylacyl-CoA racemase; Biological markers; Cystadenocarcinoma, mucinous; Urachus This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Article History: received 23 February, 2010 accepted 12 April, 2010 Corresponding Author: Wun-Jae Kim Department of Urology, Chungbuk National University College of Medicine, 62, Kaeshin-dong, Heungduk-gu, Cheongju 361-711, Korea TEL: +82-43-269-6371 FAX: +82-43-269-6144 E-mail: wjkim@chungbuk.ac.kr This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2010-0001730). Urachal adenocarcinomas are an uncommon malignancy accounting for 0.17-0.34% of all bladder cancers and 20- 39% for adenocarcinomas of the bladder [1]. Diagnosis of urachal adenocarcinoma often requires distinguishing it from primary bladder cancer and metastasis from other sites. Although distinction between them is important in clinical management, there have been few studies about this issue and no reliable markers have been described [2,3]. Alpha-methylacyl-coenzyme A racemase (AMACR) is an enzyme involved in β-oxidation of branched-chain fatty acids in mitochondria and peroxisomes, and it is frequently expressed in prostatic carcinomas and occasionally in oth- er types of carcinomas [4-6]. We report a case of urachal ad- enocarcinoma arising in the abdominal wall with ex- pression of AMACR and review the related literature. CASE REPORT A 35-year-old man had presented with a periumbilical mass 10 days earlier. On physical examination, the abdo- Korean Journal of Urology Ⓒ The Korean Urological Association, 2010 men was fully protruded, and the mass was palpable. Laboratory tests of blood and urinary analysis were within normal limits. Computed tomography (CT) revealed a well-circumscribed, multilocular cystic mass along the midline of the lower abdomen, measuring 9 cm in its max- imum diameter. The mass was located adjacent to the dome of the urinary bladder. Punctate, annular, curvilinear and peripheral calcifications were demonstrated in the cystic wall and septa (Fig. 1). The anterior portion of this mass was surrounded by the areolar fat layer of the prevesical space of Retzius and this location strongly suggested its urachal origin. There was no evidence of any other solid or- gan mass or metastatic lesion by CT. 　In cystoscopic findings, there were no abnormal mucosal lesions. Laparotomy was carried out, and an about 10 cm sized hard mass was identified. The mass was cystic, encap- sulated and extraperitoneally located in the prevesical space, and it was attached to the dome of the urinary blad- der and continued to the umbilicus with a urachal remnant. The cystic mass and urachal remnant were resected and 498 Korean J Urol 2010;51:498-500