Nongynecologic scar endometriosis with late onset during pregnancy

Nongynecologic scar endometriosis with late onset during pregnancy DOI: https://doi.org/10.25251/ecehtb95Keywords: endometriosis, pregnancy, scarAbstract Scar endometriosis is a rare form of cutaneous endometriosis that typically arises years after abdominal or pelvic surgery, most commonly presenting with cyclic pain and nodular lesions on or near surgical scars. We report the case of a 36-year-old pregnant woman who developed a painless, enlarging nodule on a midline abdominal scar, 24 years after an open appendectomy. The lesion appeared during the first trimester of pregnancy and was initially suspected to be a foreign body granuloma. Ultrasonography revealed a subcutaneous hypoechoic mass without signs of infection or encapsulation. Due to the patient’s advanced gestation, a superficial excision was performed under local anesthesia. Histopathologic examination confirmed the diagnosis of scar endometriosis with decidualized stroma, consistent with hormonally active ectopic endometrial tissue. This case is notable for its late onset, absence of typical symptoms, and development during pregnancy, highlighting the diagnostic challenges posed by atypical presentations. Dermatologists should maintain a high index of suspicion for scar endometriosis, especially in women with prior abdominal surgeries, even in the absence of classical features. References 1. Alessandro P, Luigi N, Felice S, Maria PA, Benedetto MG, Stefano A. Research development of a new GnRH antagonist (Elagolix) for the treatment of endometriosis: a review of the literature. Arch Gynecol Obstet. 2017;295(4):827-32. doi:10.1007/s00404-017-4328-6; 2. Nezhat FR, Shamshirsaz AA, Yildirim G, Nezhat C, Nezhat C. Pelvic Pain, Endometriosis, and the Role of the Gynecologist. In: Pediatric, Adolescent, & Young Adult Gynecology. 1st ed. Wiley-Blackwell; 2009. p.174-93. doi:10.1002/9781444311662.ch20; 3. Victory R, Diamond MP, Johns DA. Villar’s nodule: a case report and systematic literature review of endometriosis externa of the umbilicus. J Minim Invasive Gynecol. 2007;14(1):23-32. doi:10.1016/j.jmig.2006.07.014; 4. Machairiotis N, Stylianaki A, Dryllis G, et al. Extrapelvic endometriosis: a rare entity or an under diagnosed condition? Diagn Pathol. 2013;8(1):194. doi:10.1186/1746-1596-8-194; 5. Purvis RS, Tyring SK. Cutaneous and subcutaneous endometriosis. J Dermatol Surg Oncol. 1994;20(10):693-5. doi:10.1111/j.1524-4725.1994.tb00456.x; 6. Vellido-Cotelo R, Muñoz-González JL, Oliver-Pérez MR, et al. Endometriosis node in gynaecologic scars: a study of 17 patients and the diagnostic considerations in clinical experience in tertiary care center. BMC Womens Health. 2015;15(1):13. doi:10.1186/s12905-015-0170-9; 7. Jaime TJ, Jaime TJ, Ormiga P, Leal F, Nogueira OM, Rodrigues N. Umbilical endometriosis: report of a case and its dermoscopic features. An Bras Dermatol. 2013;88(1):121-4; 8. Tatli F, Gozeneli O, Uyanikoglu H, et al. The clinical characteristics and surgical approach of scar endometriosis: a case series of 14 women. Bosn J Basic Med Sci. 2018;18(3):275; 9. Leyland N, Casper R, Laberge P, et al. Endometriosis: diagnosis and management. J Endometriosis. 2010;2(3):107-34. doi:10.1177/228402651000200303; 10. Scholefield HJ, Sajjad Y, Morgan PR. Cutaneous endometriosis and its association with caesarean section and gynaecological procedures. J Obstet Gynaecol. 2002;22(5):553-4. doi:10.1080/0144361021000003762; 11. Isidore T, Anita NOG, Coralie MM, et al. Endometriosis beyond the pelvis: a case series of cutaneous endometriosis and literature review. Open J Obstet Gynecol. 2024;14(1):77-88. Downloads Published Data Availability Statement No datasets were generated or analyzed during the current study. Issue Section License Copyright (c) 2026 Rafael Baptista Santos, Maria João Cruz, Manuel Bernardo Costa, Diana Martins, Raquel Vilar Portugal, Maria Helena Bessa (Author) This work is licensed under a Creative Commons Attribution 4.0 International License.