{"paper_id":"270eca30-be9f-4853-b986-3559f7168e53","body_text":"Mushiake et al. Surgical Case Reports            (2023) 9:12  \nhttps://doi.org/10.1186/s40792-022-01571-x\nCASE REPORT\nThe usefulness of laparoscopic surgery \nfor inguinal endometriosis\nShu Mushiake1, Nao Kawaguchi1,2, Mitsuhiro Asakuma1*, Koji Komeda1, Tetsunosuke Shimizu1, \nFumitoshi Hirokawa1, Tomoo Shimomura2 and Sang‑Woong Lee1 \nAbstract \nBackground Inguinal endometriosis is a rare clinical disease with an unclear etiology and pathogenesis, and its \ndiagnosis requires accurate medical history‑taking and histological examination. However, surgical treatment for the \ncondition has not yet been standardized. This report presents two cases of inguinal endometriosis.\nCase presentation The first patient was a 36‑year‑old woman who complained of pain and swelling in her right \ninguinal region. Physical examination revealed a soft, tender right inguinal mass. The size of the mass repeatedly \nincreased and decreased during menstruation and did not show swelling with abdominal pressure. Magnetic reso‑\nnance imaging showed a 3.5 × 2.5 cm mass with high intensity on T2‑weighted imaging in the right inguinal canal, \nand no communication was found between the lesion site and the abdominal cavity. We diagnosed this case as \ninguinal endometriosis and managed it using an anterior approach and laparoscopic observation. The second patient \nwas a 51‑year‑old woman who presented with an intermittently painful mass in her right inguinal region. The mass \ntended to increase in size, with worsening pain before menstruation. Abdominal computed tomography revealed a \n2 × 2 cm cystic mass in the right inguinal region. We made a diagnosis of inguinal ectopic endometriosis and decided \nto operate via the totally extraperitoneal (TEP) method for excision plus transabdominal observation. The postopera‑\ntive course in both cases was uneventful with no recurrence.\nConclusions Inguinal endometriosis is a rare entity that should be suspected in patients with cyclical symptoms of \ninguinal pain and swelling that correlate with their menstrual cycle, which might otherwise be attributed to inguinal \nhernia. It is crucial to make a preoperative diagnosis based on a careful medical review, physical examination, and \nimaging studies, and to make an appropriate surgical plan. Particularly, in the case of ectopic inguinal endometriosis \ninvolving the canal of Nuck, laparoscopic observation is useful for the intraoperative diagnosis of inguinal endome‑\ntriosis to help rule out the involvement of other abdominal sites. However, it is important to select and modify the \nsurgical technique to avoid rupturing the endometrisis mass and prevent postoperative recurrence.\nKeywords Inguinal endometriosis, Laparoscopic surgery, TEP\n© The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which \npermits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the \noriginal author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or \nother third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line \nto the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory \nregulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this \nlicence, visit http:// creat iveco mmons. org/ licen ses/ by/4. 0/.\nBackground\nEndometriosis is defined as the presence of normal endo-\nmetrial mucosa outside the uterine cavity; its incidence \nin the inguinal region is reported to range from 0.07% to \n0.8% [1, 2]. Clinicians may misdiagnose inguinal endo -\nmetriosis as a hernia, lipoma, or hematoma. Preoperative \ndiagnosis relies on a careful medical review and a detailed \nphysical examination. Complete surgical excision is the \ncurative treatment and prevents recurrence [3]. However, \ninguinal endometriosis is extremely rare, and its surgi -\ncal procedure has not been standardized. Therefore, it \nis crucial to make a preoperative diagnosis and plan for \nproper surgery. We preoperatively diagnosed two cases \nof inguinal endometriosis and performed laparoscopic \nOpen Access\nSurgical Case Reports\n*Correspondence:\nMitsuhiro Asakuma\nmitsuhiro.asakuma@ompu.ac.jp\n1 Department of General and Gastroenterological Surgery, Osaka Medical \nand Pharmaceutical University Hospital, 2‑7 Daigaku‑Machi, Takatsuki, \nOsaka 569‑8686, Japan\n2 Department of Surgery, Sousei Hospital, Kadoma, Osaka, Japan\n\nPage 2 of 6Mushiake et al. Surgical Case Reports            (2023) 9:12 \nsurgery. For each case, we considered the pathogenesis \nand proper surgical treatment, including the benefits of \nlaparoscopy.\nCase presentation\nCase 1\nA 36-year-old woman complained of pain and swelling in \nher right inguinal region, which appeared 5 months prior \nto presentation. Physical examination revealed a soft, ten-\nder right inguinal mass. A key historical feature was that \nthe mass repeatedly increased and decreased with men -\nstruation. The mass did not show swelling with maneu -\nvers that increase abdominal pressure, such as coughing. \nUltrasonography showed 3.0 × 2.0  cm cystic lesion and \nmagnetic resonance imaging showed a 3.5 × 2.5  cm \nmass with high intensity on T2-weighted imaging in her \nright inguinal canal (Fig.  1), and no communication was \nfound between the lesion site and the abdominal cavity. \nWe diagnosed the case as inguinal endometriosis with \nno communication with the intra-abdominal cavity and \ndecided to operate laparoscopically.\nIntraoperative laparoscopy revealed the dilatation of \nthe hernia gate in the right lateral abdominal wall similar \nto a slit. However, as the patient was a young woman, fer-\ntility preservation was prioritized, and we decided to not \nrepair the hernia, but only to remove the mass (Fig.  2a). \nBloody ascites suggestive of endometriosis was noted in \nthe pouch of Douglas (Fig.  2b). We decided to remove \nthe mass via an anterior approach rather than a laparo -\nscopic approach, because the lesion was located near the \npubis. The boundary between the mass and surrounding \ntissue structures was well-defined (Fig.  3a). We removed \nthe mass without rupture (Fig. 3b) following laparoscopic \nobservation and confirmed that the hernial gate was not \ndilated.\nHistopathological examination revealed ectopic endo -\nmetriosis in the canal of Nuck (Fig.  4). The patient was \ndischarged without postoperative complications. Because \nbloody ascites was observed, and the presence of other \nsites of endometriosis was also suspected, the patient was \nclosely followed up and has been without recurrence for \n30  months postoperatively and the sympton of inguinal \nhernia has not been appeared.\nCase 2\nA 51-year-old woman presented with an intermit -\ntently painful mass in her right inguinal region. The \nmass tended to increase in size, and the pain worsened \nbefore menstruation. Abdominal computed tomogra -\nphy revealed a 2 × 2 cm cystic mass in her right inguinal \nregion (Fig.  5). We made a diagnosis of inguinal ectopic \nendometriosis. We decided to excise the endometri -\notic lesion via the totally extraperitoneal (TEP) method \nin addition to transabdominal observation. We inserted \nthree trocars; a 10 mm trocar at the umbilicus, a 5 mm \nabove the pubis, and another midway between the pubis \nand the umbilicus (Fig.  6). Laparoscopy revealed the \nabsence of bloody ascites and the presence of right lateral \nabdominal wall dilatation of the hernia gate (JHS clas -\nsification; right I-1) (Fig.  7). We isolated the mass after \nconfirming that only the round ligament remained on the \nperiphery (Fig.  8). After excision, we spread the mesh to \nFig. 1 a Ultrasonography showed 3.0 × 2.0 cm cystic lesion. b Magnetic resonance imaging showed a 3.5 × 2.5 cm mass with high intensity on \nT2‑weighted imaging in her right inguinal canal\n\nPage 3 of 6\nMushiake et al. Surgical Case Reports            (2023) 9:12 \n \ncover the hernia gate and reviewed the abdominal cavity \nagain. Histopathological examination revealed endome -\ntriosis (Fig.  9). The patient tolerated the procedure well \nwith no complications, and has had no recurrence after \n20 months of follow-up.\nDiscussion\nInguinal endometriosis is a rare condition, and its etiol -\nogy and pathogenesis remain unclear. Several etiological \ntheories exist regarding the developmental mechanism \nof endometriosis in the inguinal region. The first is the \n“transplantation theory” of lymphatic or hematogenous \nspread. The second theory is the “direct extension the -\nory” of direct invasion to the inguinal region. The third \nis the “metaplasia theory, ” in which endometrial tissue \nfrom the Müllerian ducts causes metaplasia of the peri -\ntoneal epithelium [2, 4]. In this report, both cases had a \nwell-defined boundary between the round ligament and \nthe mass, and the first case also involved the canal of \nNuck. These facts may be a reasonable basis for attribut -\ning their inguinal endometriosis to the metaplasia theory. \nIt is interesting that Wolfhagen et al. also demonstrated \nthe canal of the Nuck in their resection specimens, which \nis possibly an essential key to pathogenesis [5].\nIn the preoperative diagnosis of inguinal ectopic endo -\nmetriosis, it is important to interview the patient to \ndetermine whether inguinal pain becomes more severe \nwith menstruation. Although we did not measure CA125 \nFig. 2 a Inguinal hernia that required treatment was not found on laparoscopic observation of the abdominal cavity. b Bloody ascites suggestive of \nendometriosis was found in the pouch of Douglas\nFig. 3 a Boundary between the mass and the surrounding tissue was well‑defined. b Mass was removed without rupture\n\nPage 4 of 6Mushiake et al. Surgical Case Reports            (2023) 9:12 \n(a blood marker for endometriosis) in our study, CA125 \nwas elevated in approximately half of the cases [6]. It may \nappear that elevated blood CA125 is useful for preopera -\ntive diagnosis. As for the treatment plan, ectopic endo -\nmetriosis is generally treated with surgery, symptomatic \ntreatment, endocrine therapy, or approaches that com -\nbine these modalities [4 ]. To our knowledge, there is \nno established surgical technique for inguinal ectopic \nFig. 4 Collection of spindle‑shaped cells in the subserosa on hematoxylin–eosin (HE) staining and positive estrogen receptor (ER) and CD10 \nimmunostaining. Furthermore, the resected specimen was also positive for Calretinin stain\nFig. 5 Abdominal computed tomography revealed a 20 × 20 mm \ncystic mass in the right inguinal region\nFig. 6 TEP ports placement after intraperitoneal observation. A \n10 mm port at the umbilicus, 5 mm port above the pubis, and \nanother midway between the pubis and the umbilicus\n\nPage 5 of 6\nMushiake et al. Surgical Case Reports            (2023) 9:12 \n \nendometriosis, but it is important to prevent the spread \nof the lesion to surrounding organs when removing the \nmass.\nIn this report, the first case was managed using the \nanterior approach plus laparoscopic observation, and \nthe second case was managed using the TEP method \nplus abdominal observation, which combines the merits \nof both the transabdominal peritoneal approach (TAPP) \nand TEP . An advantage of laparoscopic surgery is that it \ncan be used to detect pelvic endometriosis, which can \nlead to the recurrence of inguinal ectopic endometrio -\nsis [5 ]. Laparoscopy can also be used to directly inves -\ntigate for the presence of an inguinal hernia, which may \nbe associated with inguinal endometriosis [7 , 8]. The \ntreatment of endometriosis requires complete resection \nof the endometriotic lesion. In the case of ectopic endo -\nmetriosis, complete excision of the round ligament by \nlaparoscopic surgery may be useful if the lesion extends \ninto the abdominal cavity via the round ligament [9 ]. In \nthe case of inguinal ectopic endometriosis involving the \ncanal of the Nuck, it is important to completely remove \nthe mass. Below, we consider whether the TAPP or TEP \nmethod is more suitable for laparoscopic surgery. In the \nTAPP method, it is possible that the peritoneal sheath is \npulled into the inguinal canal because of pneumoperito -\nneum. Dissecting the peritoneal sheath on the peripheral \nside of the inguinal canal may be difficult. In contrast, \nin the TEP method, the approach is performed through \nthe extraperitoneal space without incising the perito -\nneum, which allows sufficient dissection to the periph -\neral side of the inguinal canal without interfering with \nthe abdominal wall structure in the groin. Regarding \ndissection to the peripheral side of the inguinal canal, \nif the mass ruptures intraoperatively, the endometriosis \nlesion will spread. The TEP method may reduce the risk \nof intraoperative damage to the mass due to its magni -\nfying effect. In addition, the TEP method may reduce \nthe effect of endometriosis lesions on the abdominal \ncavity considering it does not incise the peritoneum. \nHence, the TEP method may be superior to the TAPP \nmethod in terms of postoperative safety and a low risk \nof recurrence.\nFig. 7 There was dilatation of the hernia gate (JHS classification; right \nI‑1), and no ascites\nFig. 8 Excised specimen was a 20 × 20‑mm cyst (white arrows), and \nthe contents of the mass were bloody. The black arrow shows the \nhernia gate. Yellow circle is tip of hernia sac. Yellow allow is inferior \nabdominal artery and vein\nFig. 9 Hematoxylin–eosin (HE) staining showing congestion, hemorrhage, and infiltration of inflammatory cells and hemosiderin in the cell wall. \nThe resected specimen was also positive for CD10 staining. Scale bar: 200 μm\n\nPage 6 of 6Mushiake et al. Surgical Case Reports            (2023) 9:12 \nIt is important not to rupture the mass, but to remove \nits contents without seeding the surrounding tissue [10]. \nIf the size of the lesion is larger than the umbilical inci -\nsion and it is difficult to remove the mass without rup -\nturing it, the operative approach should be modified by \nadding an anterior approach as shown in Case 1.\nFinally, laparoscopic observation of the abdominal cav -\nity is useful for the preoperative diagnosis of inguinal \nendometriosis to help rule out the involvement of other \nabdominal sites, as the disease has the potential to recur \nor undergo malignant transformation [8, 11].\nConclusions\nInguinal endometriosis is a rare entity that should be \nsuspected in patients with cyclical symptoms of ingui -\nnal pain and swelling that correlate with their menstrual \ncycle, which might otherwise be attributed to an ingui -\nnal hernia. It is crucial to make a preoperative diagno -\nsis from a careful medical review, physical examination, \nand imaging studies, and to make an appropriate surgi -\ncal plan. When performing surgery for inguinal endome -\ntriosis, laparoscopic observation of the abdominal cavity \nis useful for the preoperative diagnosis to help rule out \nthe involvement of other abdominal sites, considering the \npossibility of recurrence or malignant transformation. It \nis important to select and modify the surgical technique \nto avoid rupturing the mass and prevent postoperative \nrecurrence.\nAbbreviations\nTAPP  Transabdominal peritoneal approach\nTEP  Totally extraperitoneal\nAcknowledgements\nThe authors are grateful for the cooperation of the all staff engaged in patient \ntreatment. We would like to thank Editage (www. edita ge. com) for English \nlanguage editing.\nAuthor contributions\nSM designed the report, and SM drafted the manuscript. NK and MA reviewed \nand revised the manuscript. KK, TS, FH, and TS assisted in the preparation of \nthe manuscript through the interpretation and discussion of data. SWL super‑\nvised the patient’s care and preparation of the report. All authors have read \nand approved the final manuscript.\nFunding\nNot applicable.\nAvailability of data and materials\nNot applicable.\nDeclarations\nEthics approval and consent to participate\nNot applicable.\nConsent for publication\nThe patient provided written informed consent for publication of this case \nreport and accompanying images.\nCompeting interests\nSM, NK, MA, KK, TS, FH, TS, and SWL declare that they have no conflict of \ninterest.\nReceived: 23 July 2022   Accepted: 18 November 2022\nReferences\n 1. Sun ZJ, Zhu L, Lang JH. A rare extrapelvic endometriosis: inguinal endo‑\nmetriosis. J Reprod Med. 2010;55:62–6.\n 2. Jimenez M, Miles RM. Inguinal endometriosis. Ann Surg. 1960;151:903–11. \nhttps:// doi. org/ 10. 1097/ 00000 658‑ 19600 6000‑ 00014.\n 3. Horton JD, Dezee KJ, Ahnfeldt EP , Wagner M. Abdominal wall endo‑\nmetriosis: a surgeon’s perspective and review of 445 cases. Am J Surg. \n2008;196:207–12. https:// doi. org/ 10. 1016/j. amjsu rg. 2007. 07. 035.\n 4. Machairiotis N, Stylianaki A, Dryllis G, Zarogoulidis P , Kouroutou P , \nTsiamis N, et al. Extrapelvic endometriosis: a rare entity or an under \ndiagnosed condition? Diagn Pathol. 2013;8:194. https:// doi. org/ 10. 1186/ \n1746‑ 1596‑8‑ 194.\n 5. Wolfhagen N, Simons NE, de Jong KH, van Kesteren PJM, Simons MP . \nInguinal endometriosis, a rare entity of which surgeons should be \naware: clinical aspects and long‑term follow‑up of nine cases. Hernia. \n2018;22:881–6. https:// doi. org/ 10. 1007/ s10029‑ 018‑ 1797‑x.\n 6. Li SH, Sun HZ, Li WH, Wang SZ. Inguinal endometriosis: ten case reports \nand review of literature. World J Clin Cases. 2021;9(36):11406–18. https:// \ndoi. org/ 10. 12998/ wjcc. v9. i36. 11406.\n 7. Kiyak G, Ergul E, Sarikaya SM, Yazgan A. Endometriosis of the groin hernia \nsac: report of a case and review of the literature. Hernia. 2010;14:215–7. \nhttps:// doi. org/ 10. 1007/ s10029‑ 009‑ 0532‑z.\n 8. Husain F, Siddiqui ZA, Siddiqui M. A case of endometriosis presenting \nas an inguinal hernia. BMJ Case Rep. 2015. https:// doi. org/ 10. 1136/ \nbcr‑ 2014‑ 208099.\n 9. Ueda G, Matsuo Y, Omi K, Hayashi Y, Saito K, Tsuboi K, et al. A case of \ninguinal endometriosis treated with exploratory laparoscopy. Jpn J \nGastroenterol Surg. 2021. https:// doi. org/ 10. 5833/ jjgs. 2019. 0121.\n 10. Klein AE, Bauer TW, Marks KE, Belinson JL. Papillary clear cell adenocar‑\ncinoma of the groin arising from endometriosis. Clin Orthop Relat Res. \n1999;361:192–8. https:// doi. org/ 10. 1097/ 00003 086‑ 19990 4000‑ 00025.\n 11. Fedele L, Bianchi S, Frontino G, Zanconato G, Rubino T. Radical excision of \ninguinal endometriosis. Obstet Gynecol. 2007;110:530–3. https:// doi. org/ \n10. 1097/ 01. AOG. 00002 68803. 84556. 0b.\nPublisher’s Note\nSpringer Nature remains neutral with regard to jurisdictional claims in pub‑\nlished maps and institutional affiliations.","source_license":"CC0","license_restricted":false}