Abdominal wall endometriosis in a cesarean scar: a case report

Background Endometriosis affects 6–15% of reproductive‑aged women, with abdominal wall endometriosis occur‑ ring in 1–12% of extrapelvic cases. Cesarean scar endometriosis, the most common abdominal wall endometriosis subtype, arises in 0.03–3.5% of post‑cesarean patients, often presenting as cyclical pain or a palpable mass near sur‑ gical scars. Diagnostic challenges stem from nonspecific symptoms and imaging overlap with granulomas, hernias, or tumors. Case presentation A 25‑year‑old female Arab patient presented with a 1.6 cm tender subcutaneous nodule adja‑ cent to her Pfannenstiel scar, worsening during menses. Ultrasound revealed a hypoechoic nodule, while magnetic resonance imaging showed a 15 × 12 mm subcutaneous lesion with low T1 and intermediate T2 signals. Despite imaging favoring granuloma, clinical suspicion for cesarean scar endometriosis prompted wide surgical excision. Histopathology confirmed endometrial glands, stroma, and hemosiderin‑laden macrophages, confirming abdominal wall endometriosis. Postoperatively, cyclical pain resolved, with no recurrence at the 2‑month follow‑up.

Cesarean scar endometriosis, though rare, requires high clinical suspicion in patients with prior cesar‑ ean sections and cyclical symptoms. Multimodal imaging aids differentiation, but histopathology remains definitive. Surgical excision with clear margins is curative, preventing complications such as malignant transformation. This case highlights the interplay of surgical history, hormonal factors, and anatomical predisposition in cesarean scar endo‑ metriosis pathogenesis. Clinicians must prioritize early recognition and intervention to optimize outcomes in this underdiagnosed condition.

Endometriosis, Abdominal wall endometriosis, Cesarean scar, Cesarean scar endometriosis, Case report

Endometriosis, a chronic gynecologic condition charac - terized by the presence of functional endometrial glands and stroma outside the uterine cavity, affects 6–15% of reproductive-aged women globally [1, 2]. While classically involving pelvic structures such as the ovaries, uterosacral ligaments, and rectovaginal septum, extra-pelvic manifestations account for 1–12% of cases, with the abdominal wall representing the most frequent extra-genital site [3–5]. Abdominal wall endometriosis (AWE), defined as ectopic endometrial tissue localized between the parietal peritoneum and skin, most commonly arises in or adja - cent to surgical scars [6], Cesarean scar endometriosis (CSE), the predominant subtype of AWE, occurs in 0.03–3.5% of post-cesarean patients [7]. Anatomically, AWE lesions are categorized as superfi - cial (subcutaneous), intermediate (fascia-infiltrating), or Open Access © The Author(s) 2025. 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To view a copy of this licence, visit http:// creat iveco mmons. org/ licen ses/ by‑ nc‑ nd/4. 0/. Journal of Medical Case Reports *Correspondence: Ahmad Al‑Bitar [email protected]; [email protected] 1 Faculty of Medicine, Damascus University, Damascus, Syrian Arab Republic 2 Department of General Surgery, Faculty of Medicine, Damascus University, Damascus, Syrian Arab Republic 3 Department of General Surgery, University of Medical Sciences and Technology, Riyadh, Saudi Arabia Page 2 of 5Aljbawi et al. Journal of Medical Case Reports (2025) 19:239 deep (intramuscular) [8]. Clinically, patients present with cyclical pain; palpable masses; or less commonly, dysuria, dyspareunia, or infertility [3, 9–11]. Despite its association with prior surgery, scar endo - metriosis remains under-recognized, with an incidence of 0.03–0.4% following cesarean sections (C-sections), 1.08–2% after hysterectomies, and 0.06–0.7% post-episi - otomy [12, 13] Diagnostic challenges arise from its nonspecific symp - tomatology and radiographic overlap with granulomas, hematomas, incisional hernias, abscesses, and soft-tissue neoplasms [14] Consequently, a high clinical suspicion—particularly in women with cyclical pain and a history of abdominal surgery—is critical to guide timely histopathologic con - firmation and intervention [15] Here, we present a case of cesarean scar endometriosis in a 25-year-old patient, highlighting the diagnostic pit - falls, multimodal imaging findings, and definitive man - agement through surgical excision. Case presentation A 25-year-old female Arab patient presented to our hospital with a 1-year history of a stable, nongrowing subcutaneous mass in the right lower abdominal wall adjacent to her Pfannenstiel scar from a cesarean section performed 3  years prior. The mass became increasingly tender during menstruation, prompting evaluation. She reported no prior symptoms of endometriosis, mental health conditions, or relevant family history. Psychoso - cial assessment revealed no financial, cultural, or linguis - tic barriers to care. On physical examination, a firm, non-reducible 1.6 cm nodule was palpated at the right edge of the scar with - out skin discoloration, fluctuation, or size changes during coughing. Abdominal and pelvic exams were otherwise unremarkable. The timeline of her condition began with an uncomplicated C-section (time of hospital visit [T] − 3  years), followed by an asymptomatic mass first noticed at T − 1 year, cyclical pain prompting presenta - tion (T = 0), and progression to surgical intervention at T + 2 weeks. Initial ultrasound revealed a well-defined hypoechoic nodule (1.6 × 1  cm) at the scar site, raising suspicion for granuloma or endometriosis. To address diagnostic ambiguity, magnetic resonance imaging (MRI) was per - formed at T + 1 week, showing a 15 × 12 mm subcutane- ous lesion with low T1 and intermediate T2 signals, with no restricted diffusion, and mild contrast enhancement (Figs.  1, 2, 3, 4). While imaging favored inflammatory granuloma, the cyclical pain and C-section history kept abdominal wall endometriosis (AWE) high in the differ - ential. Notably, fibromatosis and soft-tissue tumors were considered less likely due to the absence of aggressive imaging features. Fig. 1 Computed tomography scan showing the lesion. Axial, coronal, and sagittal planes are presented, offering comprehensive views of the lesion’s location, size, and characteristics Fig. 2 Computed tomography scan showing the lesion. Axial, coronal, and sagittal planes are presented, offering comprehensive views of the lesion’s location, size, and characteristics Fig. 3 Computed tomography scan showing the lesion. Axial, coronal, and sagittal planes are presented, offering comprehensive views of the lesion’s location, size, and characteristics Page 3 of 5 Aljbawi et al. Journal of Medical Case Reports (2025) 19:239 Due to persistent symptoms, wide surgical excision was performed under general anesthesia at T + 2 weeks. Intraoperative findings included a 30 × 20 × 15  mm firm nodule embedded in fibro-fatty tissue beneath the scar (Fig.  5), with no evidence of a hernia. The mass was excised, and the facial defect was repaired primarily. Histopathology confirmed endometrial glands, stroma, hemosiderin-laden macrophages, and fibromyxoid tissue (Fig. 6), definitively diagnosing AWE. No malignancy was identified. Postoperatively, the patient reported immediate resolution of cyclical pain. At her 2-month follow-up (T + 2  months), the incision had healed without com - plication, and no residual mass was palpable. She was advised to undergo annual gynecologic surveillance for Fig. 4 Computed tomography scan showing the lesion. Axial, coronal, and sagittal planes are presented, offering comprehensive views of the lesion’s location, size, and characteristics Fig. 5 This figure shows irregular endometrial‑like glandular structures and stroma embedded within fibrous tissue, characteristic of endometriosis. Hemosiderin‑laden macrophages are present Fig. 6 This figure shows irregular endometrial‑like glandular structures and stroma embedded within fibrous tissue, characteristic of endometriosis. Hemosiderin‑laden macrophages are present Page 4 of 5Aljbawi et al. Journal of Medical Case Reports (2025) 19:239 endometriosis recurrence given her surgical and hormo - nal risk profile.

and conclusion Endometriosis, a chronic and enigmatic condition affect - ing 6–10% of women of reproductive age [1], manifests in diverse forms, including extra-pelvic presentations. Cesarean scar endometriosis (CSE), an iatrogenic compli- cation of cesarean section (CS), arises from the implanta - tion of endometrial tissue into surgical incisions, with an incidence of 0.03–3.5%[7] Our patient, a 25-year-old female, presented with a nodule in the right lower quadrant of her abdominal wall (AWE), the most common extra-pelvic subtype. Despite its prevalence among extra-pelvic cases, AWE remains rare, occurring in < 1% of women with endome - triosis [8]. The lesion localized to the corner of her Pfan - nenstiel scar—a transverse incision commonly used for CS—aligning with the direct implantation theory. This theory posits that endometrial cells inadvertently trans - planted during uterine surgery proliferate under hormo - nal stimuli [4, 11]. Retrospective studies corroborate this anatomical predilection: 77–84% of CSE lesions develop at incision margins, likely due to incomplete removal of endometrial debris during wound closure [2]. Notably, 80% of post-CS endometriosis cases occur at scar cor - ners [2], consistent with our patient’s presentation 3 years post-procedure [7]. While retrograde menstruation, coelomic metapla - sia, and immune dysregulation are proposed etiologies, direct implantation remains the most accepted theory for CSE [4, 11, 16]. However, the rarity of CSE despite frequent endome - trial exposure during CS underscores a multifactorial pathogenesis. Genetic predisposition, hormonal sensi - tivity, and surgical technique likely interact to promote ectopic cell survival. Pfannenstiel incisions, though cos - metically favorable, confer higher CSE risk than vertical incisions (24 versus 33 months’ latency) [2, 17, 18]. This disparity may stem from broader dissection planes in Pfannenstiel approaches, increasing tissue contami - nation and vascular disruption, which facilitate angio - genesis and endometrial cell engraftment. Additionally, cesarean scar defects (CSDs)—myometrial disconti - nuities from impaired wound healing—create niches for ectopic endometrium. Hormonal fluctuations drive cyclical hemorrhage into these defects, accelerating cyst formation; one reported CSD-associated mass expanded from 4 to 8 cm within a month [2, 7, 19]. CSE mimics granulomas, hernias, and soft-tissue tumors, necessitating multimodal imaging. Ultrasound typically reveals hypoechoic masses, while MRI detects hemorrhagic foci (T1 hypointensity, T2 hyperintensity) and defines lesion depth [4 , 20]. In our case, MRI iden - tified a 15 × 12  mm subcutaneous lesion in the right iliac fossa with low T1 and intermediate T2 signals, suggesting inflammatory or stitch granuloma. However, imaging limitations persist; histopathology remains the diagnostic gold standard. Transvaginal ultrasound (TVS) and CT aid in evaluating CSD-associated cases, with TVS identifying anechoic “niches” and CT high - lighting hemorrhagic components. Although CA125 serves as a biomarker, its negativity does not exclude endometriosis [21]. Key differentials for AWE include granuloma, fibromatosis, soft-tissue tumors, lipoma, hematoma, sebaceous cyst, incision hernia, and lymphoma [22]. For our patient, granuloma, fibromatosis, and soft- tissue tumors were considered, with endometriosis prioritized due to surgical history. Histopathology post-excision confirmed a 30 × 20x15 mm nodule with surrounding fat tissue, revealing benign endometrial glands and stroma without malignancy—a critical dis - tinction given reports of rare malignant transformation [23]. Surgical excision with 1  cm margins is definitive for symptomatic CSE, achieving > 90% symptom resolution [2]. Medical therapies (e.g., gonadotropin-releasing hor - mone [GnRH] agonists) offer temporary relief but fail to prevent recurrence. For CSD-associated cases, combined laparoscopic excision and hysteroscopic niche repair optimize fertility outcomes, while postoperative hor - monal suppression reduces recurrence risk. Malignant transformation, though rare (57% survival rate), man - dates complete resection, emphasizing the need for early intervention [7]. CSE, though rare, warrants vigilance in women with prior CS presenting with cyclical pain or masses. Pfan - nenstiel incisions and CSDs heighten risk, necessitating meticulous surgical techniques to minimize endometrial contamination and imaging-guided excision for precise management. Early diagnosis and intervention are para - mount to prevent complications, including malignancy, and to improve quality of life. This case underscores the interplay of surgical history, anatomical factors, and hor - monal influences in CSE pathogenesis, reinforcing the importance of a multidisciplinary approach in managing this enigmatic condition. Abbreviations CSE Cesarean scar endometriosis AWE Abdominal wall endometriosis MRI Magnetic resonance imaging TVS Transvaginal ultrasound GnRH Gonadotropin‑releasing hormone CSD Cesarean scar defects

Not applicable. Page 5 of 5 Aljbawi et al. Journal of Medical Case Reports (2025) 19:239 Author contributions MAJ, AAB, and LR were responsible for the drafting of the text, sourcing, and investigation results, and critical revision for important intellectual content. All authors read and approved the final manuscript. Funding Not applicable. Availability of data and materials Data sharing is not applicable to this article, as no datasets were generated or analyzed during the current study. Declarations Ethics approval and consent to participate Not applicable. Consent for publication Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor‑in‑Chief of this journal. Competing interests The authors declare that they have no competing interests. Received: 26 March 2025 Accepted: 24 April 2025

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