Vaginal polypoid endometriosis in a woman in her 30s with advanced pelvic endometriosis: A case report and literature review

A 36-year-old woman (P1 + 0) presented to the gynaecology clinic with a history of chronic abdominal pain, intermenstrual bleeding and postcoital bleeding, and secondary infertility. Her last menstrual period was regular, and she reported no abnormal discharge or systemic symptoms. She had had a normal Pap smear within the preceding year and had no personal or family history of malignancy. Her obstetric history included one uncomplicated spontaneous vaginal delivery several years prior. The patient was known to have stage IV endometriosis, following laparotomy for adhesiolysis and ovarian cystectomy secondary to bilateral endometriomas one year earlier. Histopathological examination at that time confirmed the diagnosis of endometriosis. She had since experienced recurrent pelvic pain and subfertility despite surgical and medical management. Pelvic ultrasonography demonstrated bilateral ovarian cysts consistent with endometriomas. The left ovary measured 8.7 cm × 6.9 cm, and the right ovary 4.7 cm × 3.5 cm, both exhibiting ground-glass echogenicity. The endometrial cavity contained a focal echogenic lesion suggestive of an endometrial polyp. There was no free fluid in the pouch of Douglas, and the remainder of the pelvic anatomy appeared normal. Routine laboratory investigations, including complete blood count and renal function tests, were within normal parameters. The patient was scheduled for laparoscopic bilateral ovarian cystectomy, chromopertubation, hysteroscopic polypectomy and removal of vaginal poylpoid lesions. Intraoperatively, a 2.3 cm × 1.6 cm polypoid mass with a smooth, regular surface was visualized in the posterior vaginal fornix ( Fig. 1 ). The lesion appeared well circumscribed, non-friable, and without ulceration. An excisional biopsy was performed for histopathological analysis. Fig. 1 Intraoperative view of the well-circumscribed polypoid vaginal lesion (white arrow) located in the posterior vaginal fornix and the cervix (red arrow) superiorly. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.) Fig. 1 Intraoperative view of the well-circumscribed polypoid vaginal lesion (white arrow) located in the posterior vaginal fornix and the cervix (red arrow) superiorly. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.) Laparoscopic evaluation revealed dense adhesions between the sigmoid colon and posterior uterus, as well as endometriotic deposits on the bladder peritoneum. Both ovarian cysts were adherent to the pelvic sidewalls, and the cyst walls were carefully dissected and excised from both ovaries using bipolar energy and sharp dissection. The cysts were retrieved via an endoscopic bag through the 12 mm umbilical port. Chromopertubation revealed bilateral tubal occlusion. Hysteroscopic assessment demonstrated an endometrial polyp in the posterior aspect of the endometrial cavity, which was excised using a mechanical morcellator. The procedure was completed uneventfully, and the patient had an unremarkable postoperative recovery. Histopathological examination of the vaginal lesion demonstrated endometrial glands and stroma embedded within fibrotic tissue consistent with polypoid vaginal endometriosis. The excised ovarian cysts confirmed bilateral endometriomas, and the endometrial specimen revealed a benign endometrial polyp. The patient remained well post-operatively and was advised on long-term follow-up for recurrence surveillance and fertility counselling.

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Written informed consent was obtained from the patient for the publication of this case report and accompanying image.

Endometriosis is defined by the presence of endometrial-like glands and stroma implanted outside the uterus [ 1 ]. Polypoid endometriosis is a remarkably rare histological variant characterized by the distinctive polypoid growth pattern that clinically and morphologically mimics benign or malignant neoplasms. The first documented case of polypoid endometriosis was reported by Benz et al. in 1952, occurring in the colon [ 8 ]. Mostoufizadeh and Scully later coined the term “polypoid endometriosis” in 1980, formally recognizing it as a distinct pathological entity [ 4 ]. While endometriosis affects approximately 10 % of women of reproductive age, polypoid variants represent a minute subset of cases and generally occur in women with a mean age of 52.5 years [ 9 ]. According to epidemiological data, approximately 60 % of women affected by polypoid endometriosis are postmenopausal, suggesting a potential association with hormonal influences and long-standing disease [ 9 ]. Polypoid endometriosis has been documented in a variety of sites, including the ovary, cervix, colon, ureter, and vagina [ 10 ]. The vagina represents the rarest location reported in the literature [ 11 ]. This is largely due to its relative isolation from direct peritoneal flow and its non-Müllerian epithelial lining, which makes it an unusual site for endometrial implantation [ 12 ]. Proposed mechanisms for vaginal involvement include metaplastic transformation of Müllerian rests, direct implantation following surgical manipulation, and retrograde menstruation with secondary invasion through pre-existing microfistulous tracts [ 13 ]. The rarity of vaginal lesions, therefore, suggests that multiple mechanisms may act synergistically in their development, particularly in women with severe, long-standing pelvic disease. Clinically, vaginal polypoid endometriosis may manifest with intermenstrual bleeding, postcoital spotting, dyspareunia, or as a palpable vaginal mass [ 14 ]. These symptoms often overlap with those of benign polyps, vaginal adenosis, or malignancies such as adenocarcinoma or sarcoma, which may lead to misdiagnosis [ 15 ]. In the present case, the patient had chronic pelvic pain, secondary infertility, and abnormal vaginal bleeding, symptoms that were initially attributed to advanced pelvic endometriosis and an endometrial polyp. The intraoperative identification of a smooth-surfaced, polypoid mass in the posterior vaginal fornix highlights the importance of thorough clinical assessment and intraoperative inspection in patients with severe endometriotic disease. According to Yazawa et al., the diagnosis of vaginal polypoid endometriosis is difficult to confirm exclusively on imaging findings, although some reports indicate that pelvic MRI is useful [ 16 ]. T1-weighted images demonstrate high signal intensity arising from the solid component of polypoid endometriotic lesions, while T2-weighted images reflect abundant endometrial glands resembling endometrial polyps [ 17 ]. However, these findings are not specific to polypoid endometriosis, and distinguishing it from malignant lesions can be difficult. Histopathology remains the gold standard for diagnosis [ 18 ]. Characteristically, these lesions demonstrate a combination of proliferative or secretory endometrial glands and stroma, often embedded within fibrotic tissue [ 18 ]. These findings distinguish polypoid endometriosis from malignant endometrioid or clear cell carcinomas, which may share overlapping morphological features [ 17 ]. On gross examination, these lesions are fleshy with cystic changes and haemorrhage [ 18 ]. In the present case, the histological finding of endometrial-type glands and stroma within the vaginal wall confirmed the diagnosis of vaginal polypoid endometriosis, excluding malignancy. The pathogenesis of polypoid vaginal endometriosis has been linked to prolonged estrogenic stimulation, either endogenous or exogenous, as well as previous pelvic surgery [ 5 ]. Prolonged estrogen stimulation may promote excessive endometrial proliferation, leading to the characteristic polypoid morphology [ 5 ]. Notably, the present patient had undergone prior laparotomy and cystectomy for bilateral endometriomas, suggesting that surgical manipulation might have contributed to the iatrogenic implantation of endometrial tissue in the vaginal fornix. Management of polypoid vaginal endometriosis depends on the extent of the lesion, symptom severity, and fertility considerations. Complete surgical excision remains the definitive treatment, with excellent outcomes [ 11 ]. Hormonal suppression using gonadotropin-releasing hormone (GnRH) analogues, progestins, or oral contraceptives may be used postoperatively to minimize recurrence, especially in multifocal disease [ 11 ]. Given the patient's young age and desire for fertility, conservative surgical management with lesion excision was appropriately undertaken, followed by continued surveillance. In conclusion, this case highlights a rare presentation of vaginal polypoid endometriosis discovered incidentally during laparoscopic surgery for advanced endometriosis. It underscores the importance of maintaining a high index of suspicion for atypical manifestations of endometriosis, especially in patients with a history of extensive disease or prior pelvic surgery. Careful intraoperative assessment and histopathological evaluation are essential for accurate diagnosis and avoidance of unnecessary radical intervention. Equally important is individualized decision-making in management, particularly for young women, to balance disease control with fertility preservation and quality of life.

This article was not commissioned and was peer reviewed. Vishal Bahall, an editorial board member for Case Reports in Women's Health , was not involved in editorial consideration of the manuscript and was blinded to the process.

Vishal Bahall contributed to patient care, drafted the manuscript and revised the article critically for important intellectual content. Lance De Barry contributed to patient care, drafted the manuscript, undertook the literature review and revised the article critically for important intellectual content. Both authors approved the final manuscript.

Endometriosis is a chronic, estrogen-dependent inflammatory disorder characterized by the presence of functional endometrial glands and stroma outside the uterus [ 1 ]. While it most commonly affects pelvic structures such as the ovaries, uterosacral ligaments, and peritoneum, extrapelvic and atypical presentations are occasionally reported [ 2 ]. Among these, polypoid endometriosis represents a remarkably rare histopathological variant that can simulate benign or malignant neoplasms both clinically and radiologically [ 3 ]. First described by Mostoufizadeh and Scully in 1980, polypoid endometriosis is characterized by the formation of polyp-like masses arising from hormonally responsive endometrial tissue [ 4 ]. These lesions typically present in the ovary, cervix, and colon, and are often mistaken for endometrial polyps, adenofibromas, and low-grade endometrioid adenocarcinoma [ 5 ]. Vaginal involvement is exceptionally rare, with only a handful of cases described in the literature [ 5 ]. The pathogenesis of polypoid endometriosis remains incompletely understood. Proposed mechanisms include hyperoestrogenic stimulation and iatrogenic factors associated with prior pelvic surgery [ 3 ]. Clinically, patients typically present with abnormal vaginal bleeding, pelvic pain and a vaginal mass [ 6 ]. Other stigmata of pelvic endometriosis often coexist, such as endometriomas, chronic pelvic pain, dyspareunia, infertility and hematochezia [ 6 ]. Given its rarity and variable presentation, histopathological evaluation remains the gold standard for diagnosis [ 7 ]. Recognition of this distinct entity is critical to avoid overtreatment, particularly in young women of reproductive age, where fertility preservation and long-term hormonal management are key considerations [ 7 ]. This report presents a rare case of vaginal polypoid endometriosis discovered incidentally during laparoscopic surgery for advanced-stage endometriosis. It underscores the importance of maintaining a high index of suspicion for atypical manifestations of endometriosis and highlights the need for individualized, fertility-conscious decision-making in management.

The authors declare that they have no competing interest regarding the publication of this case report.