{"paper_id":"b5589b32-814f-4e7c-93de-258e5fe20707","body_text":"Yamamoto et al. surg case rep           (2020) 6:242  \nhttps://doi.org/10.1186/s40792-020-01000-x\nCASE REPORT\nNarrow band imaging for thoracic \nendometriosis\nTakehiro Yamamoto*, Ryo Fujikawa, Yoshifumi Arai and Toru Nakamura\nAbstract \nBackground: The thoracic cavity is the most frequent site of extrapelvic endometriosis. It exhibits a wide variety of \nclinical manifestations, such as chest pain, cough, and respiratory distress, and is frequently associated with pelvic \nendometriosis. Although histological confirmation is the gold standard for a definitive diagnosis, endoscopic iden-\ntification of the affected area is often difficult. Narrow band imaging (NBI) is an imaging technique that emphasizes \nvascular structures and is reported to be useful in the diagnosis of pelvic endometriosis.\nCase presentations: A 31-year-old woman and 39-year-old woman developed a recurrent right pneumothorax \nduring their menstruation cycles. They both had no medical history suggesting pelvic endometriosis. We planned an \nelective video-assisted thoracoscopic surgery for the suspicion of thoracic endometriosis. In addition to white light \nalone, an NBI observation enhanced the microvasculature of the suspected lesions and allowed us to identify the \naffected area more clearly. Partial resections of the diaphragm were performed. Histopathological and immunohisto-\nchemical studies of each specimen confirmed the diagnosis of extrapelvic endometriosis.\nConclusions: NBI may improve the diagnostic accuracy for thoracic endometriosis, especially in clinically suspected \npatients but without a history of pelvic endometriosis.\nKeywords: Thoracic endometriosis, Catamenial pneumothorax, Narrow band imaging (NBI)\n© The Author(s) 2020. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, \nadaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and \nthe source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material \nin this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material \nis not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds \nthe permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://crea-\ntivecommons.org/licenses/by/4.0/.\nBackground\nExtrapelvic endometriosis is caused by ectopic endome -\ntrial tissue outside the abdominopelvic cavity [1]. The \nthoracic cavity is the most frequent site with a wide vari -\nety of clinical manifestations such as chest pain, cough -\ning, and respiratory distress [2, 3]. Although histological \nconfirmation is the gold standard for a definitive diagno -\nsis, endoscopic identification of the affected area is often \ndifficult similar to that of pelvic endometriosis [4]. Nar -\nrow band imaging (NBI) is an imaging technique that \nemphasizes vascular structures and has been reported to \nbe useful for the laparoscopic diagnosis of pelvic endo -\nmetriosis [5]. Here, we report two cases of thoracic \nendometriosis exhibiting a catamenial pneumothorax \nsuccessfully diagnosed by NBI.\nCase presentations\nCase 1\nA 31-year-old woman (Gravida 0, Para 0) presented \nwith a recurrent right spontaneous pneumothorax that \noccurred 4 days after the onset of menstruation. She had \na history of an ipsilateral pneumothorax treated by chest \ntube drainage 2  months prior. Her other past history \nwas negative for dysmenorrhea, pelvic pain, or any other \nsymptoms suggestive of pelvic endometriosis. Given the \nrecurrent pneumothorax without any underlying disease \nsuch as a lung cyst on chest computed tomography, we \nplanned an elective video-assisted thoracoscopic surgery \n(VATS) to rule out thoracic endometriosis during her \nnext menstrual cycle. Under thoracoscopic imaging with \nan endoscope system (Olympus Endoeye video telescope \nmodel LTF-S190-5CE, Olympus Medical Systems Corp., \nOpen Access\n*Correspondence:  take723685@gmail.com\nDepartments of General Thoracic Surgery and Pathology, Seirei \nHamamatsu General Hospital, 2-12-12 Sumiyoshi, Nakaku, Hamamatsu, \nShizuoka 430-8558, Japan\n\nPage 2 of 4Yamamoto et al. surg case rep           (2020) 6:242 \nTokyo, Japan), brownish pleural spots over the centrum \ntendineum of the diaphragm were observed with stand -\nard white light (Fig.  1a). Some of those changes were \nemphasized and more clearly visualized with dark green \nin the NBI (Fig.  1b). These morphological changes were \njudged significant based on a subjective visual inspection. \nA partial resection of the diaphragm was performed.\nCase 2\nA 39-year-old woman (Gravida 0, Para 0) presented \nwith a recurrent right spontaneous pneumothorax that \noccurred a day after the onset of menstruation. She had a \nhistory of an ipsilateral pneumothorax that resolved with \nconservative management 6  months prior. Despite lack -\ning any other history suggesting pelvic endometriosis, we \nplanned an elective VATS for the suspicion of thoracic \nendometriosis during her next menstrual cycle. Several \nbrownish spots over the lung surface (Fig.  2a) and dia -\nphragm were observed with standard white light. Those \nchanges were visualized as dark green indicating hyper -\nvascularity in the NBI (Fig.  2b). A partial resection of the \ndiaphragm was performed.\nPathological findings and postoperative course\nIn the histopathological examinations of cases 1 and 2, \nectopic endometrial lesions were found on the surface \nof the pleura and diaphragm and were accompanied by \ninflammatory granulation with hemosiderin-laden mac -\nrophages (Fig.  3a, b). Immunohistochemically, each \nectopic endometrial tissue sample was positive for estro -\ngen receptors and CD10 (Fig.  3c, d). Those results were \nconsistent with thoracic endometriosis and a gonadotro -\npin-releasing hormone agonist was administered in both \ncases. They are currently disease free at 11 months after \nthe surgery.\nConclusions\nEndometriosis is caused by ectopic endometrial tissue in \nareas other than the uterine cavity, which can lead to a \nvariety of symptoms, such as dysmenorrhea and infertil -\nity, and a histological confirmation is the gold standard \nfor a definitive diagnosis [6, 7]. However, the accuracy of \nthe visual identification using laparoscopy is vulnerable \ndepending on the surgeon’s expertise and morphological \nchange in the target lesion during the menstruation cycle \n[7, 8]. Those factors may lead to a diagnostic delay and \npoor surgical outcome [9, 10].\nThe thoracic cavity is the most frequent site of \nextrapelvic endometriosis [11]. A wide variety of clini -\ncal manifestations are seen such as chest pain, coughing, \nand respiratory distress, and may not necessarily coincide \nwith the menstrual cycle [12]. That may result in diagnos-\ntic difficulty even by VATS [1, 13–15]. As with a laparo -\nscopic biopsy for pelvic endometriosis, cyclic changes in \nthe lesion and the skill of the attending surgeon might \nalso influence the outcome [12].\nNBI is an imaging technique that emphasizes vascular \nstructures and improves the detection of microvessels \nnot clearly identified under only conventional white light \n[5]. It is widely used in the gastrointestinal diseases and \nnot costly to perform [16]. Recent studies have reported \npromising results of NBI for the diagnostic utility of \nFig. 1 Representative images of the diaphragm in case 1. Some brownish spots were more clearly visualized as dark green with NBI (arrows)\n\nPage 3 of 4\nYamamoto et al. surg case rep           (2020) 6:242 \n \ndiagnosing pelvic endometriosis by detecting hyper -\nvascularity, which is a specific disease pathology [8, 15]. \nHowever, to the best of our knowledge, to date, there \nhave been no reports of NBI having been used for tho -\nracic endometriosis.\nFig. 2 Representative images of the lung surface in case 2. Brownish spots were visualized as dark green with NBI\nFig. 3 Pathological specimens from both cases showing ectopic endometrial lesions on the surface of the diaphragm, accompanied by \ninflammatory granulation with hemosiderin-laden macrophages (a: Case 1/b: Case 2). Immunohistochemical staining of CD10 (c: Case 1) and \nestrogen receptors (d: Case 2) with a positive expression that confirms the histological nature of endometriosis\n\nPage 4 of 4Yamamoto et al. surg case rep           (2020) 6:242 \nAlthough most patients with thoracic endometrio -\nsis have been associated with pelvic endometriosis [17], \nthe present cases had no suspicious history before the \nsurgery. Therefore, we applied NBI to improve the diag -\nnostic accuracy at the time of their menstruation cycle. \nThe NBI observation enhanced the microvasculature of \nthe suspected lesions, which was not clearly identified \nby white light alone, and enabled a histological diagno -\nsis of extrapelvic endometriosis with excellent clinical \noutcomes.\nOur cases demonstrated the effectiveness of NBI for \nidentifying endometrial tissue while obtaining a better \nsurgical view with a more enhanced vascularity than with \nconventional white light alone. While histological confir -\nmation is still the gold standard of the definitive diagno -\nsis, NBI may improve the diagnostic accuracy of thoracic \nendometriosis, especially in clinically suspected patients \nbut without a history of pelvic endometriosis.\nAbbreviations\nVATS: Video-assisted thoracic surgery; NBI: Narrow band imaging.\nAcknowledgements\nWe thank Mr. John Martin for his proof-reading of the manuscript.\nAuthors’ contributions\nTY wrote this paper. YA reviewed the pathological findings. All authors read \nand approved the final manuscript.\nFunding\nNot applicable.\nAvailability of data and materials\nNot applicable.\nEthics approval and consent to participate\nNot applicable.\nConsent for publication\nWritten informed consent for the publication of the case details was obtained \nfrom our patient.\nCompeting interests\nThe authors declare that they have no competing interests.\nReceived: 23 August 2020   Accepted: 18 September 2020\nReferences\n 1. Veeraswamy A, Lewis M, Mann A, Kotikela S, Hajhosseini B, Nezhat C. \nExtragenital endometriosis. Clin Obstet Gynecol. 2010;53(2):449–66. \n 2. Bagan P , Berna P , Assouad J, Hupertan V, Le Pimpec BF, Riquet M. Value of \ncancer antigen 125 for diagnosis of pleural endometriosis in females with \nrecurrent pneumothorax. Eur Respir J. 2008;31(1):140–2. \n 3. Rousset-Jablonski C, Alifano M, Plu-Bureau G, Camilleri-Broet S, Rousset \nP , Regnard JF, et al. Catamenial pneumothorax and endometriosis-\nrelated pneumothorax: clinical features and risk factors. Hum Reprod. \n2011;26(9):2322–9. \n 4. Wykes CB, Clark TJ, Khan KS. REVIEW: Accuracy of laparoscopy in the \ndiagnosis of endometriosis: a systematic quantitative review. BJOG. \n2004;111(11):1204–12. \n 5. Gono K, Obi T, Yamaguchi M, Ohyama N, Machida H, Sano Y, et al. Appear-\nance of enhanced tissue features in narrow-band endoscopic imaging. J \nBiomed Opt. 2004;9(3):568. \n 6. Zullo F, Spagnolo E, Saccone G, Acunzo M, Xodo S, Ceccaroni M, et al. \nEndometriosis and obstetrics complications: a systematic review and \nmeta-analysis. Fertil Steril. 2017;108(4):667-72.e5. \n 7. Duffy JMN, Arambage K, Correa FJS, Olive D, Farquhar C, Garry R, et al. \nLaparoscopic surgery for endometriosis. Cochrane Database Syst Rev. \n2014. https ://doi.org/10.1002/14651 858.CD011 031.pub2(4). \n 8. Ma T, Chowdary P , Eskander A, Ellett L, McIlwaine K, Manwaring J, et al. \nCan narrowband imaging improve the laparoscopic identification of \nsuperficial endometriosis? a prospective cohort trial. J Minim Invasive \nGynecol. 2019;26(3):427–33. \n 9. Hadfield R, Mardon H, Barlow D, Kennedy S. Delay in the diagnosis of \nendometriosis: a survey of women from the USA and the UK. Hum \nReprod. 1996;11(4):878–80. \n 10. Husby GK, Haugen RS, Moen MH. Diagnostic delay in women with pain \nand endometriosis. Acta Obstet Gynecol Scand. 2003;82(7):649–53. \n 11. Rousset P , Rousset-Jablonski C, Alifano M, Mansuet-Lupo A, Buy JN, Revel \nMP . Thoracic endometriosis syndrome: CT and MRI features. Clin Radiol. \n2014;69(3):323–30. \n 12. Nezhat C, Lindheim SR, Backhus L, Vu M, Vang N, Nezhat A. Thoracic \nendometriosis syndrome: a review of diagnosis and management. JSLS. \n2019;23(3):e2019.00029. \n 13. Mehta CK, Stanifer BP , Fore-Kosterski S, Gillespie C, Yeldandi A, Meyerson \nS, et al. Primary spontaneous pneumothorax in menstruating women has \nhigh recurrence. Ann Thorac Surg. 2016;102(4):1125–30. \n 14. Legras A, Mansuet-Lupo A, Rousset-Jablonski C, Bobbio A, Magdeleinat \nP , Roche N, et al. Pneumothorax in women of child-bearing age: an \nupdate classification based on clinical and pathologic findings. Chest. \n2014;145(2):354–60. \n 15. Barrueto FF, Audlin KM, Gallicchio L, Miller C, MacDonald R, Alonsozana \nE, et al. Sensitivity of narrow band imaging compared with white light \nimaging for the detection of endometriosis. J Minim Invasive Gynecol. \n2015;22(5):846–52. \n 16. Wolfsen HC, Crook JE, Krishna M, Achem SR, Devault KR, Bouras EP , et al. \nProspective, controlled tandem endoscopy study of narrow band imag-\ning for dysplasia detection in barrett’s esophagus. Gastroenterology. \n2008;135(1):24–31. \n 17. Soriano D, Schonman R, Gat I, Schiff E, Seidman DS, Carp H, et al. Thoracic \nendometriosis syndrome is strongly associated with severe pelvic endo-\nmetriosis and infertility. J Minim Invasive Gynecol. 2012;19(6):742–8. \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}