The Korean Journal of Gastrointestinal Endoscopy Case Report 내시경으로절제한원발성직장기형종 1 예 박종하ㆍ변정식ㆍ조정현 * ㆍ김경조ㆍ예병덕ㆍ명승재ㆍ양석균ㆍ김진호 울산대학교의과대학서울아산병원내과학교실, * 병리학교실 Endoscopic Polypectomy of Primary Rectal Mature Teratoma: A Case Report Jongha Park, M.D., Jeong-Sik Byeon, M.D., Jeong-Hyeon Jo, M.D.*, Kyung-Jo Kim, M.D., Byong Duk Ye, M.D., Seung-Jae Myung, M.D., Suk-Kyun Yang, M.D. and Jin-Ho Kim, M.D. Departments of Internal Medicine and *Pathology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea Teratoma is a type of benign germ cell tumor that often contains several different types of tissue such as hair, muscle and bone, and these tissues arise from the three germinal layers. It occurs most often in the tailbones of children, the ovaries of women and the testicles of men. Primary rectal teratoma is extremely rare. We report here on a case of a 49-year-old woman with a primary rectal teratoma, and this was incidentally found during routine health screening. The rectal teratoma was a 15 mm-sized pedunculated polyp with a short stalk at the rectum, about 15 cm from anal verge as seen on CT colonography. On sigmoidoscopy and EUS, a fat and calcium containing well-defined polypoid lesion was noted in the upper rectum, with a narrow stalk attached to the colonic wall. The tumor was successfully excised by endoscopic polypectomy in order to obtain the histologic diagnosis and administer the proper treatment. (Korean J Gastrointest Endosc 2009;39:308-312) Key Words: Teratoma, Rectum, EUS, Endoscopic polypectomy 교신저자. 변정식울산대학교의과대학서울아산병원내과학교실 (138-736), 서울시송파구풍납동 388-1 전화 : 02-3010-3905 팩스 : 02-476-0824 이메일 : jsbyeon@amc.seoul.kr 접수. 2009 년 7 월 27 일승인. 2009 년 10 월 20 일 서론 술로절제하여병리검토후원발성직장기형종으로확진한 1예를경험하여문헌고찰과함께보고한다. 기형종은양성생식세포종양의한형태로, 흔히세배아층에서기원하는모발, 근육, 골성분등의다양한조직을포함하고있으며, 전체조직이분화된성숙세포로이루어진성숙기형종 (mature teratoma) 과미성숙조직이포함된미성숙기형종 (immature teratoma), 그리고, 난소갑상선종 (struma ovarii) 과같은단배엽특이기형종 (monodermal or highly specialized teratoma) 으로구분된다. 1 기형종이가장흔히발생하는곳은영유아의천추골이며, 그외생식샘인난소와고환에주로발생하고, 드물게종격동, 후복막및두경부에서발생하는것으로알려져있다. 1 원발성직장기형종은현재까지전세계적으로 54예정도가보고될정도로매우드물게발생하며주로증례기술형태로보고되고있다. 2-13 한편, 국내에는수술로절제한 3예가보고된바있다. 14-16 저자들은우연히발견된직장종괴를내시경절제 증례 49세여자가건강검진을목적으로내원하였다. 위장관증상을포함하여이상증상은없었다. 과거력에서고혈압이외의특이병력은없었으며, 수술이나외상의과거력및가족력에도특이사항은없었다. 종양표지자를포함한혈액검사결과는모두정상이었다. 단순복부 X선검사에서이상소견은관찰되지않았다. 그러나, 검진목적으로시행한 CT 가상대장내시경 (CT colonography) 에서 21 mm 크기의폴립모양병변이직장에서발견되었다. 이병변은 5 mm 굵기의짧은줄기 (stalk) 로직장벽과연결되어있었는데, 내부에지방과칼슘성분음영을포함하고있었다 (Fig. 1). 구불결장경검사에서도항문연상방 15 cm 위치의직장에짧은줄기를가진유경성폴립이관찰되었다. 이폴립은모낭을 308 The Korean Journal of Gastrointestinal Endoscopy
포함한피부와같은양상의점막으로덮여있었는데, 표면에흑색모발이나있었으며이분엽상을보였다 (Fig. 2). 병리조직학적확진을위하여내시경절제술을시행하였다 (Fig. 3). 절제된조직의육안소견은구불결장경소견과유사하였는데, 24 18 13 mm 크기로눈사람모양의이분엽상종양이었고표면은모낭및모발을포함한피부로덮여있었다. 절단면육안소견에서도종양이피부조직으로덮여있음을확인할수있었으며, 내부에노란색을띄는지방조직도관찰되었다 (Fig. 4). 현미경으로관찰하였을때직장연결부를제외한종양의표면은외배엽에서기원한모발과피지샘등의피부부속기를포함한각질을가진중층편평상피 (stratified squamous epithelium) 로덮여있었고, 내부에는중배엽에서기원한지방조직및근 섬유와혈관내피세포가관찰되어성숙기형종 (mature teratoma) 으로확진되었다 (Fig. 5). 고찰 기형종은흔히영유아의천골부에발생하며, 난소와고환등의생식샘이나, 몸의정중선을따라종격동및후복강등에서발생한다. 기형종이위장관에서발생하는것은드문데, 특히, 원발성직장기형종은현재까지전세계적으로약 50예정도만보고된매우드문질환이다. 2-16 한편, 난소기형종의장관내파열이나수술시불완전한절제로인한장관내재발의예가 Figure 1. CT colonographic finding. A 21 mm-sized, fat and calcium containing, well-defined polypoid lesion with narrow stalk (5 mm, red-cross) is noted in upper rectum. Figure 2. Endoscopic finding. A 15 mm-sized polyp with a short stalk is noted at rectum. The polyp is bilobulated and covered with skin-like mucosa including hair follicles and straight black hair. Figure 3. Endoscopic polypectomy. (A, B) Endoscopic polypectomy after saline injection is done without immediate complications. Vol. 39, No. 5 November, 2009 (308-312) 309
보고된경우도있다. 17,18 Orii 등 12 은 1864년부터 1985년까지보고된 37예의직장기형종을조사하여발표하였으며, 저자들은문헌검색을통해 Orii 등의연구이후에추가로발표된 17예의직장기형종을조사하였다 (Table 1). 2-11,13-16 자료들을살펴보면, 원발성직장기형종의진단연령은평균 41.9세이며, 8 83세의넓은연령분포를보이고있다. 이러한결과는주로영유아기에발견되는천골부기형종에비하여원발성직장기형종의 Figure 4. Macroscopic finding. The polyp contained yellow fat and vessels and the surface is covered with skin including hair follicles and hair. 진단연령이높음을보여준다. 한편, 원발성직장기형종은거의대부분여자에서진단되었으며, 남자에서발견된경우는단한예만보고되었다 (Table 1). 12 본증례도 40대여성에서진단된경우로기존증례들의역학양상과크게다르지않았다. 기형종의발생은어떠한종류의체구성세포 (body cell) 로도분화가가능한배아세포인전능성줄기세포 (totipotent stem cell) 의수정없는분화를통해이루어진다는학설이현재까지가장지지를받고있다. 1 한편, 본증례와같이정상적으로는배아세포가존재하지않는직장에서발생한기형종의경우, 발생과정중의이상에기인할것으로추정하고있다. 원시배아세포는제태기간 3 4주에제대낭 (umbilical vesicle) 벽의내배엽에서관찰되며, 뒤창자 (hindgut) 의등쪽장간막에서중간엽 (mesenchyme) 을지나생식샘능선 (gonadal ridge) 을향해이동한다. 이러한원시배아세포의생식샘이동과정중생식샘과인접구조물인부신, 요관, 직장등에비정상적으로배아세포가위치할수있고, 그결과생식샘이외의장기에서기형종이발생하는것으로추측된다. 5 지금까지보고된원발성직장기형종의증상은기형종종괴자체또는기형종표면모발의항문밖돌출 (22예 42.3%), 혈변 (18예, 34.6%), 변비 (10예, 19.2%) 등이며, 하복부통증, 복부종괴, 요통등의증상을호소하는경우도있다. 무증상인경우도있다. 2,5,7,12,14 본증례도아무런증상없이건강검진도중우연히발견된경우였다. 직장기형종의진단은내시경소견이근간을이룬다. 직장기형종의크기는 1.2 15 cm까지다양하며, 약 50% 정도가유경성폴립의형태를보인다 (Table 1). 대부분의직장기형종은 Figure 5. Microscopic finding. (A) The polyp is composed of squamous epithelium (ectodermal origin, arrow), adipose tissue (mesodermal, square) (H&E, 100). (B) The polyp is covered with keratinized squamous epithelium (ectodermal origin, square) and composed of skin appendages (hair shaft and sebaceous gland, ectodermal origin, circle). Muscle fiber is also noted (mesodermal origin, arrow) (H&E, 400). 310 The Korean Journal of Gastrointestinal Endoscopy
Table 1. Cases of Primary Rectal Teratoma in Literatures No. Author (year) Age/Sex Symptom Features of teratoma Treatment 1 Orii 12 * (1985) 66/F Constipation Pedunculated polyp (3.7 cm), Endoscopic polypectomy sessile polyp (1.5 cm) 2 Miyashita 10 (1985) 51/F Abdominal pain, hematochezia Soft mass (4.8 cm) Surgical resection 3 Hase 10 (1985) 53/F Vaginal bleeding Hard mass (8 cm) Surgical resection 4 Soejima 10 (1986) 76/F Melena 3.3 2.4 cm Endoscopic polypectomy 5 Otomo 10 (1993) 67/F Constipation Pedunculated polyp (2 cm) Endoscopic polypectomy 6 Green 3 (1993) 76/F Vaginal bleeding Pedunculated polyp (3 cm) Endoscopic polypectomy 7 Tabuchi 2 (1995) 39/F Hematochezia Pedunculated polyp (2.5 cm) Endoscopic polypectomy 8 Takao 5 (2000) 74/F Hematochezia Pedunculated polyp (1.2 cm) Endoscopic polypectomy 9 Sakurai 4 (2000) 30/F No GI symptom (miscarriage) Submucosal cystic mass (9.8 cm) Surgical resection 10 Chwalinski 6 (2001) 21/F No GI symptom Cystic mass (5.7 cm) Surgical resection 11 Park 14 (2001) 61/F Constipation Pedunculated polyp (4.2 cm) Surgical resection 12 Awata 13 (2003) 83/F Anemia Pedunculated polyp (4.5 cm) Surgical resection 13 Jeon 16 (2006) 79/F Constipation Soft mass (15 cm) Surgical resection 14 Oh 15 (2007) 62/F Constipation, hematochezia Submucosal polypoid mass (7 cm) Surgical resection 15 Jacobo Jr 9 (2007) 53/F Hematochezia Pedunculated polyp (4 cm) Endoscopic polypectomy 16 Sharma 8 (2008) 14/F Hematochezia Pedunculated polyp (7 cm) Surgical resection 17 Kumar 7 (2008) 30/F Hematochezia Pedunculated polyp (6 cm) Endoscopic polypectomy 18 Tanaka 11 (2009) 34/F Hematochezia Cystic mass with rectal wall Surgical resection penetration (3 cm) This table showed 17 rectal teratoma cases which were reported after the study of Orii 12 (Stomach and Intestine 1985;20:323-328). *Orii reported the first rectal teratoma case which was removed by endoscopic polypectomy. 상피종양 (epithelial lesion) 의형태로관찰되며, 상피하종양 (subepithelial lesion) 의형태로발현한경우는 4증례에불과하였다. 4,15 상피종양의형태란주변정상대장점막과다른양상의점막표면을의미하는데, 본증례와같이병변표면상피에서모낭과털등의피부조직이관찰될경우특징적내시경소견이라고할수있다. 내시경외에부가적인진단방법으로내시경초음파를시행할수있다. 종양의불균질한내부에코, 특히, 석회질을시사하는고에코음영이관찰될경우, 지방종, 평활근종, 림프관종, 림프종등의다른질환과감별에유용하다. 5 CT 등영상검사도종양내부의석회화음영을포함한불규칙한음영으로진단에도움을줄수있으며, 난소등다른원발부위를배제하는데특히유용하다. 본증례는 CT 가상대장내시경에서난소를비롯한생식기에이상이없으면서직장에특징적석회화음영을포함한폴립모양병변을보였고, 내시경에서는병변표면의모낭과털을확인할수있었기에원발성직장기형종을강력히의심할수있었던예이다. 한편, 병리조직학적소견이난소에서발생한기형종과원발성직장기형종감별에도움이되는경우도있는데, 일반적으로난소기형종은편평상피가종양의한구성성분으로나타나지만원발성직장기형종에서는종양이편평상피로둘러싸여있는경우가흔하다. 2 본증례에서도편평상피가종양표면을구성하고있어이런소견에부합하였다. 기형종의치료는발생부위에관계없이수술적절제가원칙이며, 그이유는염전이나, 파열, 주변장기의압박, 출혈, 감염및악성변화의우려때문이다. 기형종은일반적으로양성종양이지만, 약 0.2 2% 의난소기형종이악성변화를보이는것으로알려져있으며, 19 사춘기이후에고환에서발생한기형종의경우 29 76% 에서후복강림프절이나다른장기에전이될수있어악성종양과같이취급되기도한다. 20 원발성직장기형종의치료지침은따로정립되어있지않지만, 지금까지보고된모든원발성직장기형종은외과적혹은내시경적절제로치료하였다. 전술한바와같이기형종은일반적으로양성종양이며현재까지원발성직장기형암 (teratocarcinoma) 이보고된적은없지만, 증상유발가능성및생식샘기형종의악성변화가능성등으로유추할때절제의타당성을추론할수있다. 수술과내시경절제중선택은내시경절제가기술적으로가능한지가주요결정인자이며, 최초로직장기형종에대한내시경절제술을시행한 Orii의보고 12 이후에는 4 cm 정도이하의유경성직장기형종은대체로내시경절제술이시행되었다. 2,3,5,7,9,10 본증례에서도무증상이고크기가작아악성가능성은거의없었지만, 줄기가달려있어합병증없이쉽게내시경절제가가능할것으로판단되어병리조직학적확진을겸해내시경절제를시행하였다. 건강검진목적의대장내시경시행이증가하고있는현실을 Vol. 39, No. 5 November, 2009 (308-312) 311
감안할때, 앞으로도본증례와같이작은크기의기형종을대장내시경도중발견하게되는경우가발생할수있다. 따라서, 비록드문질환이지만이들의내시경소견및영상검사소견을숙지해두는것은다양한폴립모양병변의감별및치료계획수립에유용할것으로생각한다. 또한, 향후, 이런직장기형종증례보고들의치료경험을토대로원발성직장기형종의치료지침을마련할필요가있을것으로생각한다. 요약 기형종은양성생식세포종양의한형태로, 흔히세배아층에서기원하는모발, 근육, 골성분등의다양한조직을포함하고있으며, 전체조직이분화된성숙세포로이루어진성숙기형종 (mature teratoma) 과미성숙조직이포함된미성숙기형종 (immature teratoma), 그리고, 난소갑상선종 (struma ovarii) 과같은단배엽특이기형종 (monodermal or highly specialized teratoma) 으로구분된다. 기형종은흔히영유아의천골부에발생하며, 그외난소와고환등의생식샘이나, 몸의정중선을따라종격동및후복강등에서발생한다. 원발성직장기형종은현재까지전세계적으로약 50예정도가보고될정도로매우드물게발생하며주로증례기술형태로보고되고있고, 국내에는수술로절제한 3예가보고된바있다. 저자들은건강검진으로우연히발견된직장종괴를내시경절제술로절제하여병리검토후원발성직장기형종으로확진한 1예를경험하여문헌고찰과함께보고한다. 색인단어 : 기형종, 직장, 초음파내시경, 내시경절제술 참고문헌 1. Kumar V, Abbas A, Fausto N. Robbins and cotran pathologic basis of disease. 7th ed. Philadelphia: Elsevier Saunders, 2005. 2.Tabuchi Y, Tsunemi K, Matsuda T. Variant type of teratoma appearing as a primary solid dermoid tumor in the rectum: report of a case. Surg Today 1995;25:68-71. 3. Green JB, Timmcke AE, Mitchell WT Jr. Endoscopic resection of primary rectal teratoma. Am Surg 1993;59:270-272. 4. Sakurai Y, Uraguchi T, Imazu H, et al. Submucosal dermoid cyst of the rectum: report of a case. Surg Today 2000;30:195-198. 5. Takao Y, Shimamoto C, Hazama K, et al. Primary rectal teratoma: EUS features and review of the literature. Gastrointest Endosc 2000;51:353-355. 6. Chwalinski M, Nowacki MP, Nasierowska-Guttmejer A. Anorectal teratoma in an adult woman. Int J Colorectal Dis 2001;16:398-401. 7. Kumar B, Kumar M, Sen R, Anchal N. Mature solid teratoma of the rectum: report of a case. Surg Today 2008;38:1133-1136. 8. Sharma D, Kumar S, Tandon A, Kar AG, Kumar M, Shukla VK. Primary rectal teratoma. Surgery 2008;143:570-571. 9. Dib Jacobo J, Delago M, Cruz M. Teratoma rectal. Caso Clinico. Revista de la Sociedad Venezolana de Gstroenterologia 2006;61: 123. 10. Otomo M, Ito Y, Okabe N. A solid tearatoma of the rectum removed by endoscopic polypectomy - a case report -. Endoscopia Digestiva 1993;5:1245-1249. 11. Tanaka T, Motoba S, Sawada T, et al. A case of primary cystic teratoma in the rectum. Jpn J Gastroenterol Surg 2009;42:227-232. 12. Orii S, Matuya H, Kashiwabara H. Benign solid teratoma of the rectum: removed with endoscopic polypectomy, report of a case. Stomach and Intestine 1985;20:323-328. 13. Awata H, Izumi T, Fujishima Y. A benign solid teratoma of the rectum: a case report. Endosc Forum Dig Dis 2003;19:84-88. 14. Park KS, Kang MS, Kim YJ, Kim CH, Yoon HK. Mature teratoma of the rectum: a case report. Korean J Pathol 2001;35:83-85. 15. Oh SY, Song SC, Lee KJ, Kim YB, Suh KW. A case of a rectal teratoma. J Korean Soc Coloproctol 2007;23:129-131. 16. Jeon SY, Cho SG, Choi SK, et al. Rectal teratoma coexistent with an ovarian teratoma: a case report. J Korean Radiol Soc 2006; 54:417-420. 17. Sasaki H, Nagasako K, Harada M, Kobayashi S, Uetake K. Benign cystic teratoma of the ovary with rupture into the rectum: report of a unique rectal tumor. Dis Colon Rectum 1979;22:248-251. 18. Choi KW, Jeon WJ, Chea HB, et al. A recurred case of a muture ovarian teratoma presenting as a rectal mass. Korean J Gastroenterol 2003;42:242-245. 19. Dos Santos L, Mok E, Iasonos A, et al. Squamous cell carcinoma arising in mature cystic teratoma of the ovary: a case series and review of the literature. Gynecol Oncol 2007;105:321-324. 20. Carver B, Al-Ahmadie H, Sheinfeld J. Adult and pediatric testicular teratoma. Urol Clin North Am 2007;34:245-251. 312 The Korean Journal of Gastrointestinal Endoscopy