Endometriosis of the Lung: Case Report and Literature Review

Endometriosis of the Lung: Case Report and Literature Review | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report Endometriosis of the Lung: Case Report and Literature Review Jin Yao, Hong Zheng, Hui Nie, Jia-jia Huang, Na Tan, Cheng-fang Li, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-141435/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: Lung endometriosis is an extremely rare gynecological disease. Literature reports suggest that most patients will show generic symptoms such as hemoptysis, pneumothorax, and hemopneumothorax, which can often result in misdiagnosis. There are case reports of 18 patients with lung endometriosis describing clinical manifestation, imaging changes, treatment and prognosis. To provide further information on this rare disease, we present a case of pulmonary endometriosis and a review of lung endometriosis. Case presentation: We report on a 19-year-old female who was admitted to hospital due to repeated menstrual hemoptysis for 3 months. Computed tomography during menstruation showed patchy high-density shadows sized approximately 0.5 cm × 0.5 cm × 0.5 cm in the right middle lobe of the lung. Following menstruation, hemoptysis and changes on CT imaging disappeared. Thoracoscopic right middle lobectomy, right lower lung repair, and closed thoracic drainage were performed. Postoperative histopathology confirmed lung endometriosis. There was no recurrence of symptoms after 6 months of follow-up. Conclusions: We review the literature on factors associated with lung endometriosis, diagnosis, and treatment options. We propose that the diagnosis for lung endometriosis should be made by comprehensively integrating patient reproductive history, clinical and imaging details as well as histopathology. Surgical resection appears to be an effective treatment for lung endometriosis. Laboratory Diagnostics Pathology lung endometriosis immunophenotype differential diagnosis pathogenesis Figures Figure 1 Figure 2 Figure 3 Figure 4 Background Endometriosis refers to a common gynecological disease in which endometrial glands or stroma with normal endometrial function appear outside the endometrium. The incidence of endometriosis has increased significantly in recent years. Endometrial glands typically grow locally and bleed repeatedly, which can cause pain, infertility, as well as a series of other clinical manifestations. Extra-endometrial growth of endometrial glands or stroma most commonly occurs in pelvic cavity (mainly in the ovaries), or in adjacent tissues (e.g., broad ligament of uterus, rectovaginal lacunae, pelvic peritoneum, abdominal surgical scar, umbilical region, vagina, vulva and vermiform appendix). However, endometriosis can also occur in other organs, such as the lung, pleura, kidney, ureter, bladder, cranial cavity, and mammary gland. Notably, lung endometriosis is very rare and usually accompanies a history of miscarriage or uterine cavity surgery. Case Presentation The patient was a 19-year-old female who was admitted for hemoptysis during menstrual period for 3 consecutive months. The patient experienced hemoptysis during the first menstrual period after an abortion one year prior, and hemoptysis with the expulsion of approximately 200 ml of blood recurred in the three months prior to admission. The symptoms appeared on the third day of menstruation and disappeared after menstruation. There were no accompanying symptoms such as chest pain, respiratory distress, coughing, fever, night sweats, or weight loss. Our auxiliary examination revealed several patchy high-density shadows in the middle lobe of the right lung in computed tomography of the chest. The high-density shadows had a size of 0.5 cm × 0.5 cm × 0.5 cm (Fig. 1 a,b) .Laboratory tests assessing routine blood values, liver and renal function, as well as tumor markers, came back normal. A sputum smear test for Mycobacterium tuberculosis was also negative. A thoracoscopic right middle lobectomy, right lower lung repair, and closed thoracic drainage were carried out surgically. Tissue specimens were fixed in 10% neutral formalin, embedded in paraffin and stained with H&E. The Envison method was used for immunohistochemistry, and the antibodies used were purchased from Fuzhou Maixin Biotechnology Development Co., Ltd. Cytopathological analysis of the right middle lobe bronchial brushing found many ciliated columnar epithelial cells and a few lymphocytes, and no malignant cells were observed.Specimen observation of the tissue revealed that the size of lung tissue in the right middle lobe was 9.0 cm × 5.0 cm × 1.0 cm. The section was grey red and soft. A hemorrhagic area (1.5 cm × 0.8 cm × 0.5 cm) was seen locally (Fig. 2 a,b).Upon microscopic observation of the right middle lobe lung tissue sent for examination, hemorrhage foci were seen in the alveolar cavity, scattered glandular epithelial cells and inflammatory cells were found in the bleeding foci (Fig. 3 a,b), and glandular epithelial cells were seen in the vascular cavity of some lung tissues (Fig. 3 c), and hemosiderin deposits were seen in some alveolar cavity (Fig. 3 d). The immunohistochemical staining was CK positive (Fig. 4 a), but ER, PR, and CD10 expression was negative. Prussian blue staining for hemosiderin was also positive (Fig. 4 b). The pathological diagnosis was lung endometriosis with old hemorrhage of the right middle lobe. Discussion We analyzed this case as well as 18 other reported cases of lung endometriosis (presented in Table 1 ). The age of onset was between 19 to 54 years. Patients often sought out doctors due to repeated menstrual hemoptysis, and most patients had a history of miscarriage or uterine cavity surgery. The appearance of hemoptysis was consistent with the occurrence of the menstrual period. After menstruation, the hemoptysis subsided; consistent with this, most patients exhibited imaging changes during the menstrual period, but the imaging findings disappeared after the menstrual period. Almost all patients reported on underwent local lobectomy, and histopathology confirmed the presence of endometrial glands, interstitial cells, hemosiderin deposits, fibrous tissue hyperplasia, or similar pathological findings in the lung tissue. Some patients underwent additional immunohistochemical detection of ER, PR, CD10, or CD68, for instance, and the results suggested the presence of endometrial tissue. In all patients, hemoptysis, pneumothorax and imaging changes disappeared postoperatively, and no recurrence was reported. Endometriosis is characterized by the growth of the endometrium outside the uterine cavity. It is a common gynecological disease that affects the fertility of women of childbearing age, with an incidence of approximately 15% in women of childbearing age [ 4 ]. It is generally considered to be a hormone-dependent disease [ 3 ]. Endometriosis mostly occurs in the pelvic cavity, while it can also occur outside the pelvic cavity. A rare form of endometriosis outside the pelvic cavity is lung endometriosis, which accounts for about 20% of pleural endometriosis [ 1 , 2 ]. As early as 1938, Schwarz described pulmonary endometriosis for the first time [ 5 ]. However, it is an extremely rare disease with complex etiology and unclear pathogenesis, and as its clinical and imaging findings are not specific, it can easily be misdiagnosed. At present, several clinical features of lung endometriosis have been reported, including repeated hemoptysis, coughing, pneumothorax, hemothorax, and pulmonary nodules consistent with menstrual periods, but not all clinical features will appear at the same time. Among the above-mentioned clinical features, approximately 82% of lung endometriosis patients experience menstrual hemoptysis as their main symptom [ 6 ], while the remaining patients may present with menstrual pneumothorax, menstrual hemothorax, or other symptoms. X-ray or CT scans can assist in the diagnosis of lung endometriosis, although it can easily be misdiagnosed due to its non-specific symptoms and rare occurrence. Therefore, other diseases must be ruled out before a clear diagnosis can be made [ 7 ]. In our case, the young woman lived in an area with a high incidence of tuberculosis and had symptoms of hemoptysis, but did not have symptoms such as low-grade fever and night sweats. CT showed no nodules, and the sputum smear test for Mycobacterium tuberculosis was negative, therefore tuberculosis was excluded. The typical pathological features of endometriosis are endometrial glands, interstitium and hemosiderin deposition under the microscope [ 8 ]. However, compared with pelvic endometriosis, these microscopic features might not all be seen concurrently in lung endometriosis. Ghigna et al. [ 9 ] reported that these three characteristics appeared at the same time only in 44% cases of lung endometriosis, while in the remaining cases only endometrial stroma was found. When only a small amount of endometrial stromal is found in lung tissue, the diagnosis is rendered more difficult [ 10 ]. In addition, it is sometimes difficult to distinguish endometrial stroma and inflammatory cells by H&E staining. Therefore, immunohistochemical detection is needed to assist in the diagnosis of lung endometriosis [ 11 ]. In the case we report here, ectopic endometrium in the lung tissue led to alveolar hemorrhage, hemosiderin deposition, chronic inflammation and fibrosis due to long-term incomplete absorption or excretion. Only few glandular epithelial cells were seen in the alveolar cavity and vascular cavity, and CK markers were positive, while ER, PR, and CD10 were negative. Prussian blue staining for hemosiderin was positive. Combining the above histopathological and immunohistochemical findings with the history of miscarriage, clinical symptoms, imaging changes and the exclusion of other lung diseases, the diagnosis of lung endometriosis was made. The pathogenesis of endometriosis is still unclear, but 8 theories exist: Endometrial implant theory: This is the most common view. Sampson proposed that when the menstrual blood flows backward, the shed endometrium can enter the pelvic cavity through the fallopian tube and implants outside the endometrium [ 12 , 13 ]. Local injuries such as the cervix, vagina, and vulva can therefore easily cause endometriosis [ 14 , 15 ]; Body cavity epithelial metaplasia theory: Meyer et al. proposed that body cavity epithelium has the potential to differentiate into endometrial tissue [ 16 ]. It may be transformed into endometrial-like tissue by certain stimulations; Iatrogenic endometrium implantation: This theory suggests a type of artificial endometrial transplantation to certain parts, such as to the abdominal wall scar after cesarean section or perineal side incision after childbirth. A history of multiple uterine cavity operations, repeated abortions, tubal drainage or similar, may therefore lead to endometriosis [ 16 , 17 ]; Embryo theory: In the embryo, the accessory mesonephros, ovary germinal epithelium, pelvic peritoneum, rectovaginal septum, umbilical region, and other tissues evolve from body cavity epithelium, and they are able to differentiate into endometrioid tissue when stimulated by inflammation, which is more common on the surface of the ovary; Induction theory: Under the induction of endogenous biochemical substances, undifferentiated peritoneal tissue can be transformed into endometrial tissue; Genetic factors: Endometriosis has a certain genetic predisposition and family aggregation, and people with a family history are more likely to suffer from this disease; Immune factors: There are reports and studies that speculate that diseased stem cells play an important role in the blood spread of epithelium and long-distance implantation [ 18 , 19 ]. At present, there is no comprehensive treatment guideline for lung endometriosis. It is generally believed that treatment includes conservative drug treatment and surgical treatment. The most appropriate treatment method is selected based on the patient’s clinical symptoms, severity and requirements. The first choice for conservative treatment is Gonadotrophin releasing hormone agonist, which is now widely accepted. This treatment inhibits the release of estrogen and progesterone from the ovaries and results in a decrease in the level of estradiol in the plasma, mimicking a state of pseudomenopause in order to control the growth of lesions. However, gonadotrophin releasing hormone antagonist treatment is costly, can elicit many adverse reactions, needs to be carried out long-term, and is symptomatic rather than a cure [ 1 ]. In addition, the recurrence rate is high, and long-time treatment may also harm the patients’ ovulation and fertility [ 20 ]. Hence, most patients choose surgical treatment, especially pulmonary wedge resection. Compared with drug therapy, the recurrence rate is lower and the prognosis is better. Conclusions Our report and literature review highlights that for the diagnosis of endometriosis, the history of abortion, clinical symptoms, imaging changes, histopathology, and immunohistochemistry need to be comprehensively analyzed. Surgical resection appears to be the most effective treatment and offers a good prognosis. Abbreviations CT Computed tomography;CK:Cytokeratin; ER:Estrogen receptor; PR:Progesterone receptor Declarations Ethics approval and consent to participate Not applicable Consent for publication Written informed consent was obtained from the patient for the publication of this case report. Availability of data and materials As a case report, all data generated or analyzed are included in this article. Competing interests The authors declare that they have no competing interests. Funding The Affiliated Hospital of Zunyi Medical University, Guizhou Province, funded by the hospital, number: Yuan zi (2014) No. 36. Authors' contributions Jin Y supervised the literature search and wrote the paper. Jia H provided the interesting case that we reported. NaT performed the follow-up. HuiNie,XiaoD performed immunohistochemical tests and Figures processing. Cheng L evaluated the histopathological images and prepared the figures. Wen z provided pictures of imaging. Jin Wang,Hong Z revised manuscript as well as guidance and editing throughout the writing process. All authors have read and approved the final manuscript. Acknowledgements None Author details 1 Department of Pathology, Affiliated Hospital of Zunyi Medical University, Zunyi 563003, Guizhou, China. 2 Department of Information, Affiliated Hospital of Zunyi Medical University, Zunyi 563003, Guizhou, China. 3 Department of Imaging, Affiliated Hospital of Zunyi Medical University, Zunyi 563003, Guizhou, China. References Haruki T, Fujioka S, Adachi Y, Miwa K, Taniguchi Y, Nakamura H. Successful video-assisted thoracic surgery for pulmonary endometriosis: report of a case. Surg Today. 2007;37(2):141–4. Cramer DW, Missmer SA. The epidemiology of endometriosis. Ann N Y Acad Sci. 2002;955:11–22. Huang H, Li C, Zarogoulidis P, Darwiche K, Machairiotis N, Yang L, et al. Endometriosis of the lung: report of a case and literature review. Eur J Med Res. 2013;18(1):13. Dizerega GS, Barber DL, Hodgen GD. Endometriosis: role of ovarian steroids in initiation, maintenance, and suppression. Fertil Steril. 1980;33(6):649–53. Schwarz OH. Endometriosis of the lung. Am J Obstet Gynecol. 1938;36:887–9. Andres MP, Arcoverde FVL, Souza CCC, Fernandes LFC, Abrão MS, Kho RM. Extrapelvic endometriosis: A systematic review. J Minim Invasive Gynecol. 2020;27(2):373–89. Tong SS, Yin XY, Hu SS, Cui Y, Li HT. Case report of pulmonary endometriosis and review of the literature. J Int Med Res. 2019;47(4):1766–70. Flieder DB, Moran CA, Travis WD, Koss MN, Mark EJ. Pleuro-pulmonary endometriosis and pulmonary ectopic deciduosis: a clinicopathologic and immunohistochemical study of 10 cases with emphasis on diagnostic pitfalls. Hum Pathol. 1998;29(12):1495–503. Ghigna MR, Mercier O, Mussot S, Fabre D, Fadel E, Dorfmuller P, et al. Thoracic endometriosis: clinicopathologic updates and issues about 18 cases from a tertiary referring center. Ann Diagn Pathol. 2015;19(5):320–5. Alifano M, Legras A, Rousset-Jablonski C, Bobbio A, Magdeleinat P, Damotte D, et al. Pneumothorax recurrence after surgery in women: clinicopathologic characteristics and management. Ann Thorac Surg. 2011;92(1):322–6. Kawaguchi Y, Hanaoka J, Ohshio Y, Igarashi T, Okamoto K, Kaku R, et al. Diagnosis of thoracic endometriosis with immunohistochemistry. J Thorac Dis. 2018;10(6):3468–72. Alwadhi S, Kohli S, Chaudhary B, Gehlot K. Thoracic endometriosis -A rare cause of haemoptysis. J Clin Diagn Res. 2016;10(4):TD01–2. de Ziegler D, Borghese B, Chapron C. Endometriosis and infertility: pathophysiology and management. Lancet. 2010;376(9742):730–8. Bellelis P, Podgaec S, Abrão MS. Environmental factors and endometriosis. Rev Assoc Med Bras. 2011;57(4):448–52. Fujimoto K, Kasai H, Suga M, Sugiura T, Terada J, Suzuki H, et al. Pulmonary endometriosis which probably occurred through hematogenous metastasis after artificial abortion. Intern Med. 2017;56(11):1405–8. Rousset-Jablonski C, Alifano M, Plu-Bureau G, Camilleri-Broet S, Rousset P, Regard JF, et al. Catamenial pneumothorax and endometriosis-related pneumothorax: clinical features and risk factors. Hum Reprod. 2011;26(9):2322–9. Augoulea A, Lambrinoudaki I, Christodoulakos G. Thoracic endometriosis syndrome. Respiration. 2008;75(1):113–9. Li F, Alderman MH 3rd, Tal A, Mamillapalli R, Coolidge A, Hufnagel D, et al. Hematogenous dissemination of mesenchymal stem cells from endometriosis. Stem Cells. 2018;36(6):881–90. Zondervan KT, Becker CM, Koga K, Missmer SA, Taylor RN, Viganò P. Endometriosis. Nat Rev Dis Primers. 2018;4(1):9. L’Huillier JP. Endobronchial endometriosis Nd-YAG therapy vs drug therapy. Chest. 2005;127(2):684–5. Tables Due to technical limitations, table 1 is only available as a download in the Supplemental Files section. Supplementary Files Table1.jpg CAREchecklistEnglish2013.pdf Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-141435","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":7605518,"identity":"aa96e9b6-ddeb-44cc-a0c2-2bc5674d446c","order_by":0,"name":"Jin Yao","email":"","orcid":"https://orcid.org/0000-0002-9589-3555","institution":"Department of pathology Affiliated hospital of Zunyi medical university Guizhou province China","correspondingAuthor":false,"prefix":"","firstName":"Jin","middleName":"","lastName":"Yao","suffix":""},{"id":7605519,"identity":"ad5dcf02-bd3f-4a58-af6b-1b9c2fa13e0b","order_by":1,"name":"Hong Zheng","email":"","orcid":"","institution":"The Affiliated Hospital of Zunyi Medical University","correspondingAuthor":false,"prefix":"","firstName":"Hong","middleName":"","lastName":"Zheng","suffix":""},{"id":7605520,"identity":"38a0fa8d-2c89-435f-a591-a9b42c958aaa","order_by":2,"name":"Hui Nie","email":"","orcid":"","institution":"The Affiliated Hospital of Zunyi Medical University","correspondingAuthor":false,"prefix":"","firstName":"Hui","middleName":"","lastName":"Nie","suffix":""},{"id":7605521,"identity":"7931a051-572c-4fd8-82d3-64b58d7df78f","order_by":3,"name":"Jia-jia Huang","email":"","orcid":"","institution":"The Affiliated Hospital of Zunyi Medical University","correspondingAuthor":false,"prefix":"","firstName":"Jia-jia","middleName":"","lastName":"Huang","suffix":""},{"id":7605522,"identity":"acaeab1e-e0a7-42f9-b7fd-0ee286ab99f1","order_by":4,"name":"Na Tan","email":"","orcid":"","institution":"The Affiliated Hospital of Zunyi Medical University","correspondingAuthor":false,"prefix":"","firstName":"Na","middleName":"","lastName":"Tan","suffix":""},{"id":7605523,"identity":"27e4afd1-4bbc-423b-b342-bdb6b76811a2","order_by":5,"name":"Cheng-fang Li","email":"","orcid":"","institution":"The Affiliated Hospital of Zunyi Medical University","correspondingAuthor":false,"prefix":"","firstName":"Cheng-fang","middleName":"","lastName":"Li","suffix":""},{"id":7605524,"identity":"686f3489-0427-4cc7-8c10-8780cf1a1d04","order_by":6,"name":"Xiao-li Dong","email":"","orcid":"","institution":"The Affiliated Hospital of Zunyi Medical University","correspondingAuthor":false,"prefix":"","firstName":"Xiao-li","middleName":"","lastName":"Dong","suffix":""},{"id":7605525,"identity":"97bfa6e6-21b8-44d4-acf3-f8b6e8690e07","order_by":7,"name":"Wen Zhang","email":"","orcid":"","institution":"The Affiliated Hospital of Zunyi Medical University","correspondingAuthor":false,"prefix":"","firstName":"Wen","middleName":"","lastName":"Zhang","suffix":""},{"id":7605526,"identity":"e37355d9-75d3-40db-a751-8d2c34f6c8ac","order_by":8,"name":"Jin-jing Wang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABA0lEQVRIie3RIWvDQBTA8RcOLuaovpKyfIU3AqEibP0oNwKJSUdkbc3FDGqj+jGmL5yYSdlkYRNR20RFxkxExQItVOVaWdj99PvzeHcAlnWtOAKhAE4jMLqhbqEuTgi2eRKMWC0uXkbHZasf1nyGxjF82ejvaf7hjrzizWOYpJKDgG7xPJzUj8mU4yehkzoPGEZz6S2V81S/DyahykLkqAnlmYj7LXM5UYI40pC87k6JZqhTygWak20WNIckrZYlanE2ud/uQjhuIdBiciv7R65Mt4xXWfDL9zr2y/SrE/vI94uiarrFcNKjHgeIAdjpO5Rpvkd+WoA7ALc5M2hZlvVf/QHceFcPIonbfQAAAABJRU5ErkJggg==","orcid":"","institution":"The Affiliated Hospital of Zunyi Medical University","correspondingAuthor":true,"prefix":"","firstName":"Jin-jing","middleName":"","lastName":"Wang","suffix":""}],"badges":[],"createdAt":"2021-01-05 22:04:02","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-141435/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-141435/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":4966940,"identity":"e948ae8d-768c-4a39-9bbd-d80275f059ef","added_by":"auto","created_at":"2021-01-14 19:20:26","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":552386,"visible":true,"origin":"","legend":"a,b The results of chest CT showed: a little patchy high-density shadow in the middle lobe of the right lung (the yellow arrow).","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-141435/v1/d736a08236b01ce3a93a6c29.jpg"},{"id":4966794,"identity":"fa8579d3-95ea-4302-a3bf-054e10cc8b10","added_by":"auto","created_at":"2021-01-14 19:17:27","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":645286,"visible":true,"origin":"","legend":"a,b Macroscopic findings: The size of lung tissue in the right middle lobe was 9.0 cm x 5.0 cm x 1.0 cm. The section was grey red and soft. A hemorrhagic area (1.5 cm x 0.8 cm x 0.5 cm) was seen locally (the yellow arrow).","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-141435/v1/a516a6f19fb634e79280afb4.jpg"},{"id":4966943,"identity":"80c07bce-be6c-4348-8e9c-2b78198cc885","added_by":"auto","created_at":"2021-01-14 19:20:27","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":2472306,"visible":true,"origin":"","legend":"The image of HE. a showed hemorrhage foci were seen in the alveolar cavity, scattered glandular epithelial cells were found in the bleeding foci (100×, the yellow arrow). b Scattered glandular epithelial cells and inflammatory cells are seen in the hemorrhage(200×, the yellow arrow). c Glandular epithelial cells were seen in the vascular cavity of some lung tissues (100×, the yellow arrow).d Hemosiderin deposits were seen in some alveolar cavity (100×, the yellow arrow).","description":"","filename":"Figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-141435/v1/33034d138d04b2eed9b22b85.jpg"},{"id":4966796,"identity":"9800581f-355e-4885-a0fc-efcea873cd0f","added_by":"auto","created_at":"2021-01-14 19:17:27","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":763185,"visible":true,"origin":"","legend":"The image of immunohistochemistry. a The immunohistochemical staining was CK positive (100×, the yellow arrow).b Prussian blue staining for hemosiderin was also positive(100×, the yellow arrow).","description":"","filename":"Figure4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-141435/v1/24c620e9e0ce0f6f4c88a6e7.jpg"},{"id":13645615,"identity":"425c511b-4e33-4843-83b9-f43107aeadd5","added_by":"auto","created_at":"2021-09-17 09:20:37","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1148309,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-141435/v1/cbddb671-7a1a-4dc9-9957-101ca3ebfd72.pdf"},{"id":4967097,"identity":"4041b1b3-0732-4dd7-a8dc-6a1b218a76e4","added_by":"auto","created_at":"2021-01-14 19:23:26","extension":"jpg","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":102865,"visible":true,"origin":"","legend":"","description":"","filename":"Table1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-141435/v1/aefce2752317ef9b78a8066e.jpg"},{"id":4966942,"identity":"70b5f46b-77ad-4d1c-8c3c-4fde51dd607d","added_by":"auto","created_at":"2021-01-14 19:20:27","extension":"pdf","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":145065,"visible":true,"origin":"","legend":"","description":"","filename":"CAREchecklistEnglish2013.pdf","url":"https://assets-eu.researchsquare.com/files/rs-141435/v1/f697ff12397475515650b4fd.pdf"}],"financialInterests":"","formattedTitle":"\u003cp\u003eEndometriosis of the Lung: Case Report and Literature Review\u003c/p\u003e","fulltext":[{"header":"Background","content":" \u003cp\u003eEndometriosis refers to a common gynecological disease in which endometrial glands or stroma with normal endometrial function appear outside the endometrium. The incidence of endometriosis has increased significantly in recent years. Endometrial glands typically grow locally and bleed repeatedly, which can cause pain, infertility, as well as a series of other clinical manifestations. Extra-endometrial growth of endometrial glands or stroma most commonly occurs in pelvic cavity (mainly in the ovaries), or in adjacent tissues (e.g., broad ligament of uterus, rectovaginal lacunae, pelvic peritoneum, abdominal surgical scar, umbilical region, vagina, vulva and vermiform appendix). However, endometriosis can also occur in other organs, such as the lung, pleura, kidney, ureter, bladder, cranial cavity, and mammary gland. Notably, lung endometriosis is very rare and usually accompanies a history of miscarriage or uterine cavity surgery.\u003c/p\u003e "},{"header":"Case Presentation","content":" \u003cp\u003eThe patient was a 19-year-old female who was admitted for hemoptysis during menstrual period for 3 consecutive months. The patient experienced hemoptysis during the first menstrual period after an abortion one year prior, and hemoptysis with the expulsion of approximately 200\u0026nbsp;ml of blood recurred in the three months prior to admission. The symptoms appeared on the third day of menstruation and disappeared after menstruation. There were no accompanying symptoms such as chest pain, respiratory distress, coughing, fever, night sweats, or weight loss.\u003c/p\u003e \u003cp\u003eOur auxiliary examination revealed several patchy high-density shadows in the middle lobe of the right lung in computed tomography of the chest. The high-density shadows had a size of 0.5\u0026nbsp;cm\u0026thinsp;\u0026times;\u0026thinsp;0.5\u0026nbsp;cm\u0026thinsp;\u0026times;\u0026thinsp;0.5\u0026nbsp;cm (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea,b) .Laboratory tests assessing routine blood values, liver and renal function, as well as tumor markers, came back normal. A sputum smear test for Mycobacterium tuberculosis was also negative. A thoracoscopic right middle lobectomy, right lower lung repair, and closed thoracic drainage were carried out surgically. Tissue specimens were fixed in 10% neutral formalin, embedded in paraffin and stained with H\u0026amp;E. The Envison method was used for immunohistochemistry, and the antibodies used were purchased from Fuzhou Maixin Biotechnology Development Co., Ltd.\u003c/p\u003e\u003cp\u003eCytopathological analysis of the right middle lobe bronchial brushing found many ciliated columnar epithelial cells and a few lymphocytes, and no malignant cells were observed.Specimen observation of the tissue revealed that the size of lung tissue in the right middle lobe was 9.0\u0026nbsp;cm\u0026thinsp;\u0026times;\u0026thinsp;5.0\u0026nbsp;cm\u0026thinsp;\u0026times;\u0026thinsp;1.0\u0026nbsp;cm. The section was grey red and soft. A hemorrhagic area (1.5\u0026nbsp;cm\u0026thinsp;\u0026times;\u0026thinsp;0.8\u0026nbsp;cm\u0026thinsp;\u0026times;\u0026thinsp;0.5\u0026nbsp;cm) was seen locally (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea,b).Upon microscopic observation of the right middle lobe lung tissue sent for examination, hemorrhage foci were seen in the alveolar cavity, scattered glandular epithelial cells and inflammatory cells were found in the bleeding foci (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea,b), and glandular epithelial cells were seen in the vascular cavity of some lung tissues (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ec), and hemosiderin deposits were seen in some alveolar cavity (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ed). The immunohistochemical staining was CK positive (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea), but ER, PR, and CD10 expression was negative. Prussian blue staining for hemosiderin was also positive (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb). The pathological diagnosis was lung endometriosis with old hemorrhage of the right middle lobe.\u003c/p\u003e "},{"header":"Discussion","content":" \u003cp\u003eWe analyzed this case as well as 18 other reported cases of lung endometriosis (presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The age of onset was between 19 to 54\u0026nbsp;years. Patients often sought out doctors due to repeated menstrual hemoptysis, and most patients had a history of miscarriage or uterine cavity surgery. The appearance of hemoptysis was consistent with the occurrence of the menstrual period. After menstruation, the hemoptysis subsided; consistent with this, most patients exhibited imaging changes during the menstrual period, but the imaging findings disappeared after the menstrual period. Almost all patients reported on underwent local lobectomy, and histopathology confirmed the presence of endometrial glands, interstitial cells, hemosiderin deposits, fibrous tissue hyperplasia, or similar pathological findings in the lung tissue. Some patients underwent additional immunohistochemical detection of ER, PR, CD10, or CD68, for instance, and the results suggested the presence of endometrial tissue. In all patients, hemoptysis, pneumothorax and imaging changes disappeared postoperatively, and no recurrence was reported.\u003c/p\u003e \u003cp\u003eEndometriosis is characterized by the growth of the endometrium outside the uterine cavity. It is a common gynecological disease that affects the fertility of women of childbearing age, with an incidence of approximately 15% in women of childbearing age [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. It is generally considered to be a hormone-dependent disease [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Endometriosis mostly occurs in the pelvic cavity, while it can also occur outside the pelvic cavity. A rare form of endometriosis outside the pelvic cavity is lung endometriosis, which accounts for about 20% of pleural endometriosis [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. As early as 1938, Schwarz described pulmonary endometriosis for the first time [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. However, it is an extremely rare disease with complex etiology and unclear pathogenesis, and as its clinical and imaging findings are not specific, it can easily be misdiagnosed.\u003c/p\u003e \u003cp\u003eAt present, several clinical features of lung endometriosis have been reported, including repeated hemoptysis, coughing, pneumothorax, hemothorax, and pulmonary nodules consistent with menstrual periods, but not all clinical features will appear at the same time. Among the above-mentioned clinical features, approximately 82% of lung endometriosis patients experience menstrual hemoptysis as their main symptom [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], while the remaining patients may present with menstrual pneumothorax, menstrual hemothorax, or other symptoms. X-ray or CT scans can assist in the diagnosis of lung endometriosis, although it can easily be misdiagnosed due to its non-specific symptoms and rare occurrence. Therefore, other diseases must be ruled out before a clear diagnosis can be made [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. In our case, the young woman lived in an area with a high incidence of tuberculosis and had symptoms of hemoptysis, but did not have symptoms such as low-grade fever and night sweats. CT showed no nodules, and the sputum smear test for Mycobacterium tuberculosis was negative, therefore tuberculosis was excluded.\u003c/p\u003e \u003cp\u003eThe typical pathological features of endometriosis are endometrial glands, interstitium and hemosiderin deposition under the microscope [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. However, compared with pelvic endometriosis, these microscopic features might not all be seen concurrently in lung endometriosis. Ghigna et al. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] reported that these three characteristics appeared at the same time only in 44% cases of lung endometriosis, while in the remaining cases only endometrial stroma was found. When only a small amount of endometrial stromal is found in lung tissue, the diagnosis is rendered more difficult [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. In addition, it is sometimes difficult to distinguish endometrial stroma and inflammatory cells by H\u0026amp;E staining. Therefore, immunohistochemical detection is needed to assist in the diagnosis of lung endometriosis [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. In the case we report here, ectopic endometrium in the lung tissue led to alveolar hemorrhage, hemosiderin deposition, chronic inflammation and fibrosis due to long-term incomplete absorption or excretion. Only few glandular epithelial cells were seen in the alveolar cavity and vascular cavity, and CK markers were positive, while ER, PR, and CD10 were negative. Prussian blue staining for hemosiderin was positive. Combining the above histopathological and immunohistochemical findings with the history of miscarriage, clinical symptoms, imaging changes and the exclusion of other lung diseases, the diagnosis of lung endometriosis was made.\u003c/p\u003e \u003cp\u003eThe pathogenesis of endometriosis is still unclear, but 8 theories exist:\u003c/p\u003e \u003cp\u003e \u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eEndometrial implant theory: This is the most common view. Sampson proposed that when the menstrual blood flows backward, the shed endometrium can enter the pelvic cavity through the fallopian tube and implants outside the endometrium [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Local injuries such as the cervix, vagina, and vulva can therefore easily cause endometriosis [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e];\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eBody cavity epithelial metaplasia theory: Meyer et al. proposed that body cavity epithelium has the potential to differentiate into endometrial tissue [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. It may be transformed into endometrial-like tissue by certain stimulations;\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eIatrogenic endometrium implantation: This theory suggests a type of artificial endometrial transplantation to certain parts, such as to the abdominal wall scar after cesarean section or perineal side incision after childbirth. A history of multiple uterine cavity operations, repeated abortions, tubal drainage or similar, may therefore lead to endometriosis [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e];\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eEmbryo theory: In the embryo, the accessory mesonephros, ovary germinal epithelium, pelvic peritoneum, rectovaginal septum, umbilical region, and other tissues evolve from body cavity epithelium, and they are able to differentiate into endometrioid tissue when stimulated by inflammation, which is more common on the surface of the ovary;\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eInduction theory: Under the induction of endogenous biochemical substances, undifferentiated peritoneal tissue can be transformed into endometrial tissue;\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eGenetic factors: Endometriosis has a certain genetic predisposition and family aggregation, and people with a family history are more likely to suffer from this disease;\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eImmune factors: There are reports and studies that speculate that diseased stem cells play an important role in the blood spread of epithelium and long-distance implantation [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e \u003cp\u003eAt present, there is no comprehensive treatment guideline for lung endometriosis. It is generally believed that treatment includes conservative drug treatment and surgical treatment. The most appropriate treatment method is selected based on the patient\u0026rsquo;s clinical symptoms, severity and requirements. The first choice for conservative treatment is Gonadotrophin releasing hormone agonist, which is now widely accepted. This treatment inhibits the release of estrogen and progesterone from the ovaries and results in a decrease in the level of estradiol in the plasma, mimicking a state of pseudomenopause in order to control the growth of lesions. However, gonadotrophin releasing hormone antagonist treatment is costly, can elicit many adverse reactions, needs to be carried out long-term, and is symptomatic rather than a cure [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. In addition, the recurrence rate is high, and long-time treatment may also harm the patients\u0026rsquo; ovulation and fertility [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Hence, most patients choose surgical treatment, especially pulmonary wedge resection. Compared with drug therapy, the recurrence rate is lower and the prognosis is better.\u003c/p\u003e "},{"header":"Conclusions","content":" \u003cp\u003eOur report and literature review highlights that for the diagnosis of endometriosis, the history of abortion, clinical symptoms, imaging changes, histopathology, and immunohistochemistry need to be comprehensively analyzed. Surgical resection appears to be the most effective treatment and offers a good prognosis.\u003c/p\u003e "},{"header":"Abbreviations","content":" \u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eComputed tomography;CK:Cytokeratin; ER:Estrogen receptor; PR:Progesterone receptor\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e "},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWritten informed consent was obtained from the patient for the publication of this case report.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs a case report, all data generated or analyzed are included in this article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe Affiliated Hospital of Zunyi Medical University, Guizhou Province, funded by the hospital, number: Yuan zi (2014) No. 36.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eJin Y supervised the literature search and wrote the paper. Jia H provided the interesting case that we reported. NaT performed the follow-up. HuiNie,XiaoD performed immunohistochemical tests and Figures processing. Cheng L evaluated the histopathological images and prepared the figures. Wen z provided pictures of imaging. Jin Wang,Hong Z revised manuscript as well as guidance and editing throughout the writing process. All authors have read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor details\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e1 Department of Pathology, Affiliated Hospital of Zunyi Medical University, Zunyi 563003, Guizhou, China.\u003c/p\u003e\n\u003cp\u003e2 Department of Information, Affiliated Hospital of Zunyi Medical University, Zunyi 563003, Guizhou, China.\u003c/p\u003e\n\u003cp\u003e3 Department of Imaging, Affiliated Hospital of Zunyi Medical University, Zunyi 563003, Guizhou, China.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eHaruki T, Fujioka S, Adachi Y, Miwa K, Taniguchi Y, Nakamura H. Successful video-assisted thoracic surgery for pulmonary endometriosis: report of a case. Surg Today. 2007;37(2):141\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCramer DW, Missmer SA. The epidemiology of endometriosis. Ann N Y Acad Sci. 2002;955:11\u0026ndash;22.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHuang H, Li C, Zarogoulidis P, Darwiche K, Machairiotis N, Yang L, et al. Endometriosis of the lung: report of a case and literature review. Eur J Med Res. 2013;18(1):13.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDizerega GS, Barber DL, Hodgen GD. Endometriosis: role of ovarian steroids in initiation, maintenance, and suppression. Fertil Steril. 1980;33(6):649\u0026ndash;53.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchwarz OH. Endometriosis of the lung. Am J Obstet Gynecol. 1938;36:887\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAndres MP, Arcoverde FVL, Souza CCC, Fernandes LFC, Abr\u0026atilde;o MS, Kho RM. Extrapelvic endometriosis: A systematic review. J Minim Invasive Gynecol. 2020;27(2):373\u0026ndash;89.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTong SS, Yin XY, Hu SS, Cui Y, Li HT. Case report of pulmonary endometriosis and review of the literature. J Int Med Res. 2019;47(4):1766\u0026ndash;70.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFlieder DB, Moran CA, Travis WD, Koss MN, Mark EJ. Pleuro-pulmonary endometriosis and pulmonary ectopic deciduosis: a clinicopathologic and immunohistochemical study of 10 cases with emphasis on diagnostic pitfalls. Hum Pathol. 1998;29(12):1495\u0026ndash;503.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGhigna MR, Mercier O, Mussot S, Fabre D, Fadel E, Dorfmuller P, et al. Thoracic endometriosis: clinicopathologic updates and issues about 18 cases from a tertiary referring center. Ann Diagn Pathol. 2015;19(5):320\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlifano M, Legras A, Rousset-Jablonski C, Bobbio A, Magdeleinat P, Damotte D, et al. Pneumothorax recurrence after surgery in women: clinicopathologic characteristics and management. Ann Thorac Surg. 2011;92(1):322\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKawaguchi Y, Hanaoka J, Ohshio Y, Igarashi T, Okamoto K, Kaku R, et al. Diagnosis of thoracic endometriosis with immunohistochemistry. J Thorac Dis. 2018;10(6):3468\u0026ndash;72.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlwadhi S, Kohli S, Chaudhary B, Gehlot K. Thoracic endometriosis -A rare cause of haemoptysis. J Clin Diagn Res. 2016;10(4):TD01\u0026ndash;2.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ede Ziegler D, Borghese B, Chapron C. Endometriosis and infertility: pathophysiology and management. Lancet. 2010;376(9742):730\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBellelis P, Podgaec S, Abr\u0026atilde;o MS. Environmental factors and endometriosis. Rev Assoc Med Bras. 2011;57(4):448\u0026ndash;52.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFujimoto K, Kasai H, Suga M, Sugiura T, Terada J, Suzuki H, et al. Pulmonary endometriosis which probably occurred through hematogenous metastasis after artificial abortion. Intern Med. 2017;56(11):1405\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRousset-Jablonski C, Alifano M, Plu-Bureau G, Camilleri-Broet S, Rousset P, Regard JF, et al. Catamenial pneumothorax and endometriosis-related pneumothorax: clinical features and risk factors. Hum Reprod. 2011;26(9):2322\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAugoulea A, Lambrinoudaki I, Christodoulakos G. Thoracic endometriosis syndrome. Respiration. 2008;75(1):113\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi F, Alderman MH 3rd, Tal A, Mamillapalli R, Coolidge A, Hufnagel D, et al. Hematogenous dissemination of mesenchymal stem cells from endometriosis. Stem Cells. 2018;36(6):881\u0026ndash;90.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZondervan KT, Becker CM, Koga K, Missmer SA, Taylor RN, Vigan\u0026ograve; P. Endometriosis. Nat Rev Dis Primers. 2018;4(1):9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eL\u0026rsquo;Huillier JP. Endobronchial endometriosis Nd-YAG therapy vs drug therapy. Chest. 2005;127(2):684\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eDue to technical limitations, table 1 is only available as a download in the Supplemental Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"lung endometriosis, immunophenotype, differential diagnosis, pathogenesis","lastPublishedDoi":"10.21203/rs.3.rs-141435/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-141435/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eLung endometriosis is an extremely rare gynecological disease. Literature reports suggest that most patients will show generic symptoms such as hemoptysis, pneumothorax, and hemopneumothorax, which can often result in misdiagnosis. There are case reports of 18 patients with lung endometriosis describing clinical manifestation, imaging changes, treatment and prognosis. To provide further information on this rare disease, we present a case of pulmonary endometriosis and a review of lung endometriosis.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eCase presentation: \u003c/strong\u003eWe report on a 19-year-old female who was admitted to hospital due to repeated menstrual hemoptysis for 3 months. Computed tomography during menstruation showed patchy high-density shadows sized approximately 0.5 cm × 0.5 cm × 0.5 cm in the right middle lobe of the lung. Following menstruation, hemoptysis and changes on CT imaging disappeared. Thoracoscopic right middle lobectomy, right lower lung repair, and closed thoracic drainage were performed. Postoperative histopathology confirmed lung endometriosis. There was no recurrence of symptoms after 6 months of follow-up. \u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConclusions: \u003c/strong\u003eWe review the literature on factors associated with lung endometriosis, diagnosis, and treatment options. We propose that the diagnosis for lung endometriosis should be made by comprehensively integrating patient reproductive history, clinical and imaging details as well as histopathology. Surgical resection appears to be an effective treatment for lung endometriosis.\u0026nbsp;\u003c/p\u003e","manuscriptTitle":"Endometriosis of the Lung: Case Report and Literature Review","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2021-01-14 19:17:25","doi":"10.21203/rs.3.rs-141435/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"bef40f49-825a-4300-9ea4-cc14ed873cf4","owner":[],"postedDate":"January 14th, 2021","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":1882742,"name":"Laboratory Diagnostics"},{"id":1882743,"name":"Pathology"}],"tags":[],"updatedAt":"2021-01-14T19:17:26+00:00","versionOfRecord":[],"versionCreatedAt":"2021-01-14 19:17:25","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-141435","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-141435","identity":"rs-141435","version":["v1"]},"buildId":"WvIrzKhiLBfengagbw6Ux","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}