{"paper_id":"6a01d302-86ed-470b-913a-2f03625c6839","body_text":"Journal of Case Reports and Images in Obstetrics and Gynecology, Volume 11, Issue 2, 2025; Pages 55–58. ISSN: 2582-0249\nJ Case Rep Images Obstet Gynecol 2025;11(2):55–58.   \nwww.ijcriog.com\nHuang et al. 55\nCLINICAL IMAGE  PEER REVIEWED | OPEN ACCESS\nCyclically bleeding umbilical mass: A case of primary  \numbilical endometriosis\nJoyce Huang, Michelle Lu, Komal Soin\nCASE REPORT \nA 28-year-old woman presented initially to an urgent \ncare clinic with a small mass protruding out of the \numbilicus. The lesion was diagnosed as a skin tag and \nexcised with minimal bleeding. Eight months later, she \npresented to our family medicine clinic for the growth \nof two similar masses in the umbilicus that now exuded \nblood. They were characterized as fibrous skin-colored \npapules and were associated with mild pain and pruritus \n(Figure 1).\nJoyce Huang1, Michelle Lu2, Komal Soin3\nAffiliations: 1School of Medicine, University of Hawaii John A. \nBurns School of Medicine, Honolulu, HI, USA; 2Department \nof Surgery, Oregon Health and Sciences University, Portland, \nOR, USA; 3Department of Family Medicine and Community \nHealth, University of Hawaii John A. Burns School of Medicine, \nHonolulu, HI, USA.\nCorresponding Author: Komal Soin, MD, MPH, Department \nof Family Medicine and Community Health, University of Ha-\nwaii, Pali Momi Outpatient Center, 98-1005 Moanalua Rd Spc \n3030, Aiea, HI 96701, USA; Email: ksoin@hawaii.edu\nReceived: 03 September 2025\nAccepted: 22 December 2025\nPublished: 31 December 2025\nUpon examination, there was no tenderness to \npalpation, no deep abdominal pain, no nausea or \nvomiting, no purulent discharge from the site, and \nno fever, flank pain, or dysuria. The patient denied \nany history of trauma to the area. The patient has no \nsignificant past medical history. She has a negative \nfamily history of melanoma and other skin cancers. At \nthis time, the patient was referred to dermatology for a \nrecurring skin lesion.\nAfter the visit, via secure digital communication, the \npatient later noted that the onset of bleeding from the \numbilical lesion coincides with her menses and resolves \nwithin four days with the completion of her menstrual \nperiod. Her menses are regular, occurring every 28–30 \ndays and lasting for seven days. The initial four days are \nmarked by heavy bleeding, clots, and significantly painful \nabdominal cramping, and the latter three days consist of \nlight spotting.\nA shave biopsy was performed at her dermatology visit \nwhich confirmed the diagnosis: umbilical endometriosis. \nShe was referred to general surgery and underwent \nsurgical excision of her umbilical endometriosis and \nprimary closure of the fascial defect which successfully \nremoved the lesion. Laparoscopy was offered to explore \nthe abdominal cavity for peritoneal endometriosis, but \nthe patient declined.\nFollowing this diagnosis, the patient was also referred \nto OB/GYN for management of primary dysmenorrhea \nand endometriosis and started combined oral \ncontraceptives. At OB/GYN follow-up one month later, \nthe patient reported having a light, pain-free period and \ndenied any further umbilical lesions or bleeding.\nDISCUSSION\nEndometriosis is a benign condition involving the \nimplantation of ectopic endometrial tissue outside of the \nuterus and has a prevalence of 6–11% in the United States \n[1]. While endometriosis most commonly manifests as \nshallow peritoneal implants, it may be found all over the \nabdominal cavity and can affect bladder, bowel, omentum, \nlung, heart, and even brain. In fact, 12% of cases of \nendometriosis present with extra-genital implants [2, 3]. \nOf these, umbilical endometriosis (UE), or Villar’s nodule, \nas described in 1886 by Villar, is the most common [4]. \nGiven the overall rarity of the condition, awareness of UE \nis important for the primary care provider, gynecologist, \nFigure 1: Physical exam of umbilicus reveals two adjacent, \nfibrous, skin colored/pink bleeding papules less than 1 cm in \nsize.\n\nJournal of Case Reports and Images in Obstetrics and Gynecology, Volume 11, Issue 2, 2025; Pages 55–58. ISSN: 2582-0249\nJ Case Rep Images Obstet Gynecol 2025;11(2):55–58.   \nwww.ijcriog.com\nHuang et al. 56\nor general surgeon who may be presented with patients \nwith this condition first.\nUmbilical endometriosis presents with an umbilical \nlesion located in the cutaneous or subcutaneous plane \nthat is discolored brown, purple, or red due to bleeding \n[1, 4, 5]. Just as the endometrial lining of the uterus \nproliferates and sheds with the menstrual cycle, these \nectopic endometrial implants also consist of functional \ntissue that are responsive to hormonal fluctuations \n[6]. This underlying mechanism accounts for why our \npatient noticed blood oozing from her umbilicus during \nher menses. Other than bleeding, the most commonly \nreported symptoms include pain and swelling of the \nnodule, and are most noticeable during menstruation [5]. \nUmbilical endometriosis generally appears in women \nof reproductive age; a systematic review by Dridi et al. \nreported a mean age of 37.9 years, with a range of 28.5 \nto 47.5. Comparatively, our 28 -year-old patient is on the \nlower end of this age range, which may in part reflect the \nvarying hormonal and environmental factors that are \nrequired for clinical presentation in different individuals. \nIt is reported that about 33% of women with umbilical \nendometriosis have received a previous diagnosis \nof endometriosis [4, 5]. Our patient had not been \npreviously diagnosed but complained of heavy bleeding \nand significant pain with menses that improved with \nhormonal contraceptive use, a clinical pattern consistent \nwith the disease. \nAs our patient does not have any surgical history, this \nwould be considered primary umbilical endometriosis \n[4, 5]. Primary UE represents almost 75% of all cases of \nUE and the mechanism behind its pathogenesis is vague. \nOn the other hand, secondary umbilical endometriosis \noccurs much more clearly due to the seeding of surgical \nscars with uterine tissue following procedures such as \nepisiotomy, cesarean section, and laparoscopy [7, 8]. \nMany theories have attempted to explain the pathogenesis \nof endometriosis and likewise UE. Embryonic remnants \nin the urachus and umbilical vessels may better explain \ncases of isolated umbilical endometriosis, wherein \ninflammation around the endometrial implant causes \nshedding and passage to the umbilicus via the umbilical \nvenous system. More commonly, endometriosis has been \nexplained via the theory of retrograde menstruation, \nwherein endometrial tissue flows backwards through \nthe fallopian tubes during menstruation, seeding the \nabdominal cavity and presumably the umbilicus [5]. In \nfact, the prevalence of UE with co-existing pelvic implants \nis much higher than that of isolated UE, which lends more \nevidence to this theory [4]. \nThere is a thought that UE travels via the same \nintra-abdominal currents initiated by large bowel \nperistalsis and respiratory movements that disseminate \novarian epithelial cells and Sister Mary Joseph nodules \n[4]. These malignancies can present similarly to UE. \nDifferential diagnosis of an umbilical lesion also includes \nmelanocytic nevus, incarceration of an umbilical hernia, \npyogenic granuloma, urachal residual, and melanoma [2, \n5, 9]. Our patient’s lesion was initially misdiagnosed as a \nskin tag and later a hemangioma before being biopsied. \nWhile initial assessment is a clinical workup, the gold \nstandard for diagnosis of cutaneous endometriosis requires \nbiopsy. Histological diagnosis is made by the presence of \ntwo of the following features of either endometrial-like \nglands, endometrial stroma, or hemosiderin pigment [1, \n5, 7, 10]. Cases with concomitant pelvic endometriosis \nmay also have elevated levels of CEA and CA125 \ntumor markers. Ultrasound and magnetic resonance \nimaging (MRI) have been useful imaging techniques \nfor characterizing and finding endometrial lesions. \nUmbilical nodules appear as a spherical finding within \nthe dermal-epidermal layer with varied echogenicity on \nultrasound. Magnetic resonance imaging in particular is \nhelpful in studying deep pelvic endometriosis which show \nfibrous lesions with varied enhancement that are hypo or \nisointense on T1 and T2 [2].\nThe mean time from onset of symptoms to diagnosis \nand treatment has been reported to be 13.3 months. \nThis delay in treatment is significant as the risk of future \nmalignancy from UE has been reported to be about 3% \n[4, 9]. Thus, timely workup and biopsy is important for \ndiagnosis and ruling out malignancy.\nThere is no standardized regimen for this condition \nsince it is so rare [11]. The definitive management for \numbilical endometriosis is surgical excision and repair of \nany disrupted local structures. Radical surgery with wide \nlocal excision is the preferred treatment and involves \ncomplete removal of the umbilicus and nodule whereas \npartial omphalectomy spares the umbilicus. Medical \nmanagement alone with hormone analogues has not \nshown reliable results, perhaps due to lack of vascular \naccessibility and penetrance. However, pharmacotherapy \n(oral contraceptives, GnRH agonists/antagonists) may \nreduce endometrioma size. The literature reports that \nthe recurrence rate of UE after surgical treatment is \nvery low with no significant difference between radical \nor partial omphalectomy or with medical treatment [4, \n5, 12]. Accordingly, a systematic review reported the \neffectiveness of surgical excision in 67.6% of patients [10]. \nCONCLUSION\nThis case demonstrates the rare case of a recurrent \numbilical lesion in a young woman of reproductive age \nthat was initially misdiagnosed. Recurrent dermatologic \nlesions or those in which the diagnosis is unclear should \nbe followed up with a proper workup and biopsy in order \nto rule out malignancy. This case brings awareness to an \noverall rare condition and underlies the importance of \nkeeping a broad differential and early referral services.\nKeywords: Cutaneous endometriosis, Cyclical bleed -\ning, Dysmenorrhea, Umbilical endometriosis, Umbilical \nmass\n\nJournal of Case Reports and Images in Obstetrics and Gynecology, Volume 11, Issue 2, 2025; Pages 55–58. ISSN: 2582-0249\nJ Case Rep Images Obstet Gynecol 2025;11(2):55–58.   \nwww.ijcriog.com\nHuang et al. 57\nHow to cite this article\nHuang J, Lu M, Soin K. Cyclically bleeding umbilical \nmass: A case of primary umbilical endometriosis. J \nCase Rep Images Obstet Gynecol 2025;11(2):55–58.\nArticle ID: 100220Z08JH2025\n*********\ndoi: 10.5348/100220Z08JH2025CI\nREFERENCES\n1. Moradi Y, Shams-Beyranvand M, Khateri S, \nGharahjeh S, Tehrani S, Varse F, et al. A systematic \nreview on the prevalence of endometriosis in women. \nIndian J Med Res 2021;154(3):446–54.\n2. Sahli H, Boularab J, Mandour JE, Allali N, Chat \nL, Haddad SE. Primary umbilical endometriosis: \nCase report and literature review of an unusual \ncause of catamenial umbilical pain. Radiol Case Rep \n2022;17(6):2133–6.\n3. Chamié LP, Ribeiro DMFR, Tiferes DA, de Macedo \nNeto AC, Serafini PC. Atypical sites of deeply \ninfiltrative endometriosis: Clinical characteristics and \nimaging findings. Radiographics 2018;38(1):309–28.\n4. Dridi D, Chiaffarino F, Parazzini F, Donati A, Buggio \nL, Brambilla M, et al. Umbilical endometriosis: A \nsystematic literature review and pathogenic theory \nproposal. J Clin Med 2022;11(4):995.\n5. Capasso L, Sciascia V, Loiaco G, Guida G, Iarrobino \nF, Di Lillo C, et al. Primary subcutaneous umbilical \nendometriosis: Case report and review of the \nliterature. Case Rep Surg 2020;2020:8899618.\n6. Tsamantioti ES, Mahdy H. Endometriosis. In: \nStatPearls. Treasure Island (FL): StatPearls \nPublishing; 2025.\n7. Pramanik SR, Mondal S, Paul S, Joycerani D. Primary \numbilical endometriosis: A rarity. J Hum Reprod Sci \n2014;7(4):269–71.\n8. Steck WD, Helwig EB. Tumors of the umbilicus. \nCancer 1965;18:907–15.\n9. Hirata T, Koga K, Kitade M, Fukuda S, Neriishi K, \nTaniguchi F, et al. A national survey of umbilical \nendometriosis in Japan. J Minim Invasive Gynecol \n2020;27(1):80–7.\n10. Fuentes HD, Quijano C, Negrete CR. Umbilical \nendometriosis: A case report and review of the \nliterature. International Journal of Research in \nMedical Sciences 2021;9(5):1485–8.\n11. Yao J, Zheng H, Nie H, Li CF, Zhang W, Wang JJ. \nEndometriosis of the lung: A case report and review of \nliterature. World J Clin Cases 2023;11(18):4326–33.\n12. Makena D, Obura T, Mutiso S, Oindi F. Umbilical \nendometriosis: A case series. J Med Case Rep \n2020;14(1):142.\n*********\nAcknowledgments\nWe would like to thank the patient who graciously \nallowed us to share her story to bring attention to a rare \npresentation of a common gynecologic condition.\nAuthor Contributions\nJoyce Huang  – Conception of the work, Design of the \nwork, Drafting the work, Revising the work critically \nfor important intellectual content, Final approval of the \nversion to be published, Agree to be accountable for all \naspects of the work in ensuring that questions related \nto the accuracy or integrity of any part of the work are \nappropriately investigated and resolved\nMichelle Lu – Conception of the work, Design of the \nwork, Drafting the work, Revising the work critically \nfor important intellectual content, Final approval of the \nversion to be published, Agree to be accountable for all \naspects of the work in ensuring that questions related \nto the accuracy or integrity of any part of the work are \nappropriately investigated and resolved\nKomal Soin – Conception of the work, Design of the \nwork, Drafting the work, Revising the work critically \nfor important intellectual content, Final approval of the \nversion to be published, Agree to be accountable for all \naspects of the work in ensuring that questions related \nto the accuracy or integrity of any part of the work are \nappropriately investigated and resolved\nGuarantor of Submission\nThe corresponding author is the guarantor of submission.\nSource of Support\nNone.\nConsent Statement\nWritten informed consent was obtained from the patient \nfor publication of this article.\nConflict of Interest\nAuthors declare no conflict of interest.\nData Availability\nAll relevant data are within the paper and its Supporting \nInformation files.\nCopyright\n© 2025 Joyce Huang et al. This article is distributed \nunder the terms of Creative Commons Attribution \nLicense which permits unrestricted use, distribution \nand reproduction in any medium provided the original \nauthor(s) and original publisher are properly credited. \nPlease see the copyright policy on the journal website for \nmore information.\n\nJournal of Case Reports and Images in Obstetrics and Gynecology, Volume 11, Issue 2, 2025; Pages 55–58. ISSN: 2582-0249\nJ Case Rep Images Obstet Gynecol 2025;11(2):55–58.   \nwww.ijcriog.com\nHuang et al. 58\nAccess full text article on\nother devices\nAccess PDF of article on\nother devices\n\nSubmit your manuscripts at\nwww.edoriumjournals.com","source_license":"CC0","license_restricted":false}