{"paper_id":"a0ddb911-6425-41bb-8bfd-f0586a7c85fb","body_text":"www.ogscience.org172\nReceived: 2013.6.27.   Revised: 2013.9.1.  Accepted: 2013.9.16.\nCorresponding author: Mi-La Kim\nDepartment of Obstetrics and Gynecology, CHA Gangnam \nMedical Center, CHA University, 566 Nonhyeon-ro, Gangnam-gu, \nSeoul 135-913, Korea\nTel: +82-2-3468-3677 Fax: +82-2-558-1112\nE-mail: mila76@naver.com\nArticles published in Obstet Gynecol Sci are open-access, distributed under the terms of \nthe Creative Commons Attribution Non-Commercial License (http://creativecommons.\norg/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, \nand reproduction in any medium, provided the original work is properly cited.\nCopyright © 2014 Korean Society of Obstetrics and Gynecology \nIntroduction\nEndometriosis is defined as growth of endometrial tissue \noutside the uterine cavity. This condition has a prevalence \nof 10% to 20% in women of reproductive age, with occur -\nrence mainly in the pelvic organs, particularly the ovaries, \npouch of Douglas, and pelvic peritoneum [1]. Additionally, \nendometriosis can also occur in extrapelvic organs such as \nthe gastrointestinal and urinary tracts, and the thoracic cavity, \numbilicus, abdominal wall incisions, central nervous system, \nbone, episiotomy scars, and abdominal wall, and rarely, in the \ninguinal canal [2,3]. Candiani et al. [4] reviewed 958 patients \nwho had endometriosis and reported that only 0.6% of pa -\ntients had inguinal endometriosis. Due to its rarity, inguinal \nendometriosis is often misdiagnosed or overlooked. Its most \ncommon symptoms are palpable inguinal mass, often accom-\npanied by change of mass size and inguinal pain related to \nmenstrual cycle [2,4]. Most cases of inguinal endometriosis \nare associated with previous surgery in the uterine cavity [2,5]. \nIn Korea, only 6 patients in 4 case reports have been reported \nto have inguinal endometriosis [6-9]. We report an additional \ncase of right inguinal endometriosis in a patient with no pre-\nvious history of gynecologic surgery; this patient was treated \nby a general surgeon using a wide excision. \nCase report\nA 40-year-old nulliparous woman presented with a pain -\nful mass in her right inguinal area. The mass had grown for \n2 years and had occasionally been tender, especially during \nmenstrual cycles. The patient had no specific medical or surgi-\ncal history. She experienced regular menstruation at 30-day \nintervals and experienced menorrhagia. Her menstruation \nperiod lasted 7 days.\nPhysical examination revealed a non-erythematous swol -\nlen and tender mass measuring approximately 2×2 cm \nlocated lateral and superior to the pubic tubercle. The size \nInguinal endometriosis in a patient without a previous \nhistory of gynecologic surgery\nDa Hee Kim\n1\n, Min Jung Kim\n1\n, Mi-La Kim\n1\n, Jong Taek Park\n1\n, Ji Hyun Lee\n2\nDepartments of \n1\nObstetrics and Gynecology, \n2\nGeneral Surgery, CHA Gangnam Medical Center, CHA University, Seoul, Korea\nEndometriosis, defined as growth of endometrial stroma and glands outside the uterine cavity, is a chronic and recurrent \ndisease that affects patients’ quality of life. Ectopic endometrial tissue can proliferate at any location in the body, but \nthe pelvic organs and peritoneum are the most frequent implantation sites. Among extrapelvic endometriosis, inguinal \nendometriosis is a very rare gynecologic condition usually associated with previous pelvic surgery. Endometriosis should \nbe preoperatively distinguished from other inguinal masses using computed tomography, magnetic resonance imaging, \nor ultrasonography. Here, we report a case of right inguinal endometriosis in a patient with no previous history of \ngynecologic surgery; in addition, we have provided a brief review of relevant literature.\nKeywords: Endometriosis; Inguinal; Round ligament; Ultrasonography\nCase Report\nObstet Gynecol Sci 2014;57(2):172-175\nhttp://dx.doi.org/10.5468/ogs.2014.57.2.172\npISSN 2287-8572 · eISSN 2287-8580\n\nwww.ogscience.org 173\nDa Hee Kim, et al. Inguinal endometriosis without gynecologic surgery\nand position of the mass remained unchanged, even when \nthe patient coughed or changed positions. The patient also \nreported intermittent vaginal spotting, for which she had \nundergone simultaneous transvaginal and inguinal ultraso -\nnography.\nThe transvaginal ultrasonography revealed two left ovarian \ncysts measuring 1.0 cm that seemed to be endometrioma or \nhemorrhagic corpus luteal cysts (Fig. 1A, B). Inguinal ultra -\nsonography showed an ill-defined hypoechoic lesion (size, \n1.1×1.2 cm) in the right pubic area, with increased vascular-\nity (Fig. 1C, D). She underwent repeated inguinal ultrasonog-\nraphy during her menstrual period. She felt tenderness and \nswelling of the lesion, but there was no change of mass size \non inguinal ultrasonography. After being informed about the \npresence of hemangioma or arteriovenous malformation, \nthe patient opted for surgical excision of the inguinal mass.\nAn oblique skin incision was performed along the line \nrunning from the pubic tubercle to the anterior superior \niliac spine, at the superior margin of the inguinal ligament. \nAfter identification of the femoral vessels, the hard mass \nwas widely excised to include a part of the round ligament. \nChocolate-colored fluid was drained from the hard cystic \nmass during the procedure, and the mass was connected \nwith the intraperitoneal round ligament at the inguinal \ncanal. The inguinal canal was opened and the extraperito -\nneal portion of the round ligament was resected by gentle \ntraction and then cutting at the level of the internal ingui -\nnal ring. The proximal stump was fixed to the surrounding \nfibrous structure of the inguinal canal. Histological examina-\ntion showed a cuff of endometrial stroma surrounding the \nendometrial glands with hemorrhaging from smooth muscle \nand fibrous tissues (Fig. 2). After 2 months of the surgery, \nthe patient’s pain completely resolved and she was fully \nrecovered without complications. Considering the possibility \nof recurrence of the inguinal endometriosis and progression \nof the ovarian endometrioma, we recommended her to use \nthe oral contraceptives and planned regular follow-up. \nFig. 1. Transvaginal ultrasonographic findings of the adnexa and inguinal mass. (A) Right ovary was grossly normal. Left ovary showed \ntwo low-echoic cysts. (B) Doppler transvaginal ultrasonographic findings of the left ovarian cyst. The longitudinal and transverse view \nshowed two low-echoic cysts of 1.0 cm size. (C) Inguinal ultrasonographic findings of the inguinal mass. The longitudinal and transverse \nviews show an ill-defined hypoechoic lesion (size, 1.1×1.2 cm). (D) On Doppler ultrasonographic findings showed increased vascularity of \nthe mass in the right pubic area.\nA  C\nB\nRight Left\nD\n\nwww.ogscience.org174\nVol. 57, No. 2, 2014\nDiscussion\nInguinal endometriosis is a rare clinical condition occurring in \nonly 0.6% of women [4]. Patients with inguinal endometriosis \ncomplain of inguinal mass and pain, in particular, acute pain \nduring menstrual cycles [2,4].\nInguinal endometriosis is usually concomitant with pelvic \nendometriosis [4,10], suggesting a similar pathogenesis for \nboth conditions. Clausen and Nielsen [11] suggested several \npossible theories, including implantation of endometrial tis -\nsue by transtubal regurgitation during the menstrual cycle, \nmetastasis via venous or lymphatic channels, congenital hor-\nmonal activation of embryonal cells from the Müllerian duct, \nmetaplasia of mesothelial cells, and direct extension from the \npelvis along the round ligament. In the case of inguinal endo-\nmetriosis, the right side is more commonly affected than the \nleft, and is often associated with inguinal hernia, and its oc -\ncurrence on both sides is rare [4,5,8,12]. The reasons for the \nright-predominance are unclear. Sun et al. [13] proposed two \ndifferent theories: 1) the sigmoid colon protects the left ingui-\nnal canal and 2) endometrial cells remain on the right side for \na longer period due to clockwise flow of intraperitoneal fluid. \nOur patient exhibited right-sided inguinal endometriosis, the \nmost common presentation.\nDifferential diagnosis is essential in cases of suspected \ninguinal mass. Causes of inguinal mass include hernia, \nlymphadenopathy, neuroma, abscess, hydroceles, hematoma, \nlymphoma, lipoma, sarcoma, subcutaneous cysts, and cancer \n[9]. Computed tomography (CT), magnetic resonance imaging \n(MRI), and ultrasonography are useful diagnostic tools. The \nCT appearance of inguinal endometriosis is often not specific \n[9,14], presenting as either solid, cystic, or complex (i.e., the \nsame density as muscle). MRI is more accurate than CT . Gaeta \net al. [14] described two MRI patterns for inguinal endome -\ntriosis. Type I pattern consist of cystic hyperintense lesions, on \nboth T1- and T2-weighted images. Type 2 lesions have solid \ncomponents, showing a high signal intensity on T1-weighted \nimages and either hypointensity or moderate hyperintensity \non T2-weighted images with some “shading signs” for cystic \nlesions [14]. The ultrasonographic findings of inguinal endo-\nmetriosis are variable. Round or oval cystic masses, represent-\ning intracystic bleeding associated with menstruation are \nfound in most cases, although homogeneously hypoechoic \nsolid or combined cystic and solid masses have also been de-\nscribed [9]. The differential diagnosis of cystic masses includes \ninguinal hernia and hydrocele, and solid masses should be \ndifferentiated from sarcoma, lymphoma, hematoma, and ab-\nscesses. Since no available diagnostic imaging tools are spe-\ncific for inguinal endometriosis, differential diagnosis based \non imaging results must be combined with a careful review of \nthe history of cyclic menstrual pain associated with inguinal \nmass [9,14]. Fine-needle aspiration cytology allows accurate \npreoperative diagnosis and exclusion of malignancy and can \nbe useful in selected cases [9,15]. \nPatients with inguinal endometriosis may have a history of \ngynecologic or abdominal surgery [2,5,10]. In the absence \nFig. 2. Microscopic findings of the excised specimen of inguinal endometriosis. The endometrial glands are surrounded by a cuff of endo -\nmetrial stroma, with hemorrhage involving smooth muscle and fibrous tissue in the round ligament. (A) H&E, ×40; (B) H&E, ×200.\nA  B\n\nwww.ogscience.org 175\nDa Hee Kim, et al. Inguinal endometriosis without gynecologic surgery\nof a surgical history, however, inguinal endometriosis may be \nmisdiagnosed as another groin diseases and managed by a \ngeneral surgeon. In our case, the patient had no history of \nprevious surgery, and ultrasonograph showed an ill-defined \nhypoechoic lesion with increased vascularity. We made a \npresumptive diagnosis of hemangioma or arteriovenous mal-\nformation and referred the patient to a general surgeon for \ntreatment. If inguinal endometriosis been correctly diagnosed \npreoperatively, the patient could have undergone laparoscopic \nsurgery rather than wide excision of the inguinal area. It is \ntherefore important to consider inguinal endometriosis in the \ndifferential diagnosis in patients with inguinal mass, even if \nthere is no history of gynecologic or abdominal surgery.\nThe treatment for inguinal endometriosis is radical surgical \nexcision of the lesion and the extraperitoneal round ligament \n[12]. In patients with concomitant inguinal endometriosis \nand pelvic endometriosis, which occurs in most cases, either \nlaparoscopy or laparotomy can be employed for the exci -\nsion. However, no such associated disease is present, neither \nlaparoscopy nor laparotomy is necessary [11,13]. Hormonal \ntherapy is recommended in addition to surgery, as it plays an \nimportant role in preventing recurrence of endometriosis [7].\nIn conclusion, inguinal endometriosis is a very rare disease \ncompared to pelvic endometriosis. Nonetheless, extrapelvic \nendometriosis should be considered in the differential diagno-\nsis in cases in which women are of reproductive age and pres-\nent with an inguinal mass, even in those without a history of \ngynecologic surgery. Pain associated with the menstrual cycle \nand characteristic ultrasonographic findings also are helpful \nfor diagnosis.\nConflict of interest\nNo potential conflict of interest relevant to this article was \nreported.\nReferences\n  1. Goldman MB, Cramer DW. The epidemiology of endome-\ntriosis. Prog Clin Biol Res 1990;323:15-31. \n  2. Seydel AS, Sickel JZ, Warner ED, Sax HC. Extrapelvic \nendometriosis: diagnosis and treatment. Am J Surg \n1996;171:239. \n  3. Cullen TS. Adenomyoma of the round ligament. Bull \nJohns Hopkins Hosp 1896;7:112-4.\n  4. Candiani GB, Vercellini P , Fedele L, Vendola N, Carinelli \nS, Scaglione V . Inguinal endometriosis: pathogenetic and \nclinical implications. Obstet Gynecol 1991;78:191-4. \n  5. Majeski J. Scar endometriosis manifested as a recurrent \ninguinal hernia. South Med J 2001;94:247-9. \n  6. Whang JD, Park CS, Bae DS, Lee JH, Noh JS, Kim JS, et \nal. Two cases of endometriosis in the extraperitoneal \nportion of the uterine round ligament. Korean J Obstet \nGynecol 1999;42:189-93.\n  7. Lee SE, Jo DH, Moon SH, Chong HI, Shin SI, Kim HG, et \nal. A case of inguinal endometriosis in the absence of \nprevious gynecologic surgery. Korean J Obstet Gynecol \n2008;51:261-4.\n  8. Lim MC, Choi JY , Lee DO, Yoo JW, Park SY , Seo SS. Ingui-\nnal endometriosis connected to intraperitoneal round \nligament: complete excision with extraperitoneal wide \ndissection. Korean J Obstet Gynecol 2008;51:1533-8.\n  9. Yang DM, Kim HC, Ryu JK, Lim JW, Kim GY . Sonographic \nfindings of inguinal endometriosis. J Ultrasound Med \n2010;29:105-10. \n10. Wong WS, Lim CE, Luo X. Inguinal endometriosis: an \nuncommon differential diagnosis as an inguinal tumour. \nISRN Obstet Gynecol 2011;2011:272159. \n11. Clausen I, Nielsen KT. Endometriosis in the groin. Int J \nGynaecol Obstet 1987;25:469-71. \n12. Fedele L, Bianchi S, Frontino G, Zanconato G, Rubino T. \nRadical excision of inguinal endometriosis. Obstet Gyne-\ncol 2007;110(2 Pt 2):530-3. \n13. Sun ZJ, Zhu L, Lang JH. A rare extrapelvic endometriosis: \ninguinal endometriosis. J Reprod Med 2010;55:62-6. \n14. 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