Caesarean scar endometriosis: how to make an accurate diagnosis

Caesarean scar endometriosis is a rare condition characterised by the presence of endometrial tissue within a surgical scar following a caesarean section. A woman in her late 30s presented with a painful lump beneath her caesarean section skin scar, worsening during menstruation. Despite a previous incision and drainage procedure for a 'scar abscess', the symptoms persisted. Ultrasound imaging revealed a cystic lesion beneath the scar. A diagnosis of scar endometriosis was made, and surgical excision was performed. The patient remained symptom-free at 2-year follow-up postsurgery. Histopathology confirmed the presence of endometrial glands and stroma within the scar tissue. This case demonstrates that a reliable diagnosis of caesarean section endometriosis could be made with a triad of symptoms of a cyclic painful mass at the site of a caesarean section scar. Imaging is helpful in excluding other differential diagnoses. Diagnosis can be confirmed with histopathology and treated with complete surgical excision.

Surgical and Percutaneous Image-Guided Therapies of Abdominal Wall Endometriosis: A Systematic Review of Current Evidence

OBJECTIVE

Despite various surgical and nonsurgical strategies for abdominal wall endometriosis, the lack of definitive guidance on optimal treatment choice leads to clinical uncertainty. This review scrutinizes the safety and efficacy of abdominal wall endometriosis treatments to aid in decision-making.

DATA SOURCES

We performed a systematic literature review of PubMed, Embase, and Cochrane Library databases from 1947 until December 2023.

METHODS OF STUDY SELECTION

A comprehensive literature search identified studies that assessed both surgical and nonsurgical interventions, including high-intensity focused ultrasound (HIFU), cryoablation, radiofrequency ablation, and microwave ablation. This review is registered in NIHR-PROSPERO (CRD 42023494969). Local tumor control (LTC), local pain relief (LPR), and adverse events (AE) were recorded.

TABULATION, INTEGRATION, AND RESULTS

This review included 51 articles among 831 identified. All study designs were considered eligible for inclusion. A total of 2674 patients are included: 2219 patients (83%) undergoing surgery, and 455 (17%) undergoing percutaneous interventions (342 HIFU, 103 cryoablation, 1 radiofrequency ablation, 9 microwave ablation). Follow-up length was 18 months in median, ranging from 1 to 235 months. Overall LTC rates ranged from 86% to 100%. Surgical interventions consistently demonstrated the highest rate of LTC with a median rate of 100%, and LPR with a median rate of 98.2% (95% confidence interval [CI]: 93.9-97.7). HIFU showed median LTC and LPR rates, respectively of 95.65% (95% CI, 87.7-99.9) and 76.1% (95% CI, 61.8-90.4); and cryoablation of 85.7% (95% CI, 66.0-99.9) and 79.2% (95% CI, 67.4-91.03). Minor AE was reported after surgery in 17.5% of patients (225/1284) including 15.9% (199/1284) of mesh implantation; 76.4% (239/313) after HIFU; and 8.7% (9/103) after cryoablation. Severe AE was reported in 25 patients in the surgery group and 1 in the percutaneous group.

CONCLUSION

The safety profile and efficacy of nonsurgical interventions support their clinical utility for management of abdominal wall endometriosis.

Radiology State-of-the-art Review: Endometriosis Imaging Interpretation and Reporting

Endometriosis is a common condition impacting approximately 190 million individuals and up to 50% of women with infertility globally. The disease is characterized by endometrial-like tissue located outside of the uterine corpus, which causes cyclical hemorrhage, inflammation, and fibrosis. Based on clinical suspicion or findings at routine transvaginal pelvic US or other prior imaging, dedicated imaging for endometriosis may be warranted with MRI or advanced transvaginal US. Deep endometriosis (DE) in the pelvis includes evaluation for stromal and fibrotic components and architectural distortion resulting from fibrosis and tethering. It is a disease requiring a compartment-based, pattern-recognition approach. MRI has the benefit of global assessment of the pelvis and is effective in assessing for features of malignancy and for evaluating extrapelvic locations. Transvaginal US has the advantage of dynamic maneuvers to assess for adhesions and may achieve higher spatial resolution for assessing the depth of bowel wall invasion. T1-weighted MRI evaluation increases the specificity of diagnosis by identifying hemorrhagic components, but the presence of T1 signal hyperintensity is not essential for diagnosing DE. Endometriosis is a disease with a broad spectrum; understanding the mild through advanced manifestations, including malignancy evaluation, is within the scope and breadth of radiologists' interpretation.

Effectiveness and complication rates of high intensity focused ultrasound treatment for abdominal wall endometriosis: A systematic review

In this review, a systematic literature search on the effectiveness and complication rates of ultrasound-guided and magnetic resonance-guided high-intensity focused ultrasound (USg-/MRgHIFU) for abdominal wall endometriosis (AWE) was conducted in six databases in May/June 2023. Original articles of (non)randomized trials, cohort studies, case-control studies and case series published in peer-reviewed journals were included. Of the included studies the level of evidence (LoE) and methodological quality using the ROBINS-I and IHE-QAT was assessed. Primary outcomes were non-perfused volume ratio (NPV%), lesion size, pain scores, side effects and complication rates according to Society of Interventional Radiology (SIR) guidelines. Secondary outcomes were recurrence and re-intervention rates. Seven cohort studies (one of good methodological quality) (LoE 3) on USgHIFU were included (n = 212, AWE lesions = 240-245). Six months after USgHIFU treatment, pain scores were reduced with 3.3-5.2 points (baseline: 5.1-6.8, n = 135). Self-limiting side effects were pain (85.7 % (114/133)) and swelling (34.6 % (46/133)) in the treatment area. Complications occurred in 17.7 % (32/181), all of which were minor. Recurrence occurred in 12.8 % (11/86). Three of these seven cohort studies compared USgHIFU (n = 61) with surgical excision (n = 74). Pooled results showed no significant differences in pain scores, complications (resp. 26.3 % (10/38) vs. 32.6 % (15/46) (p = 0.53)) and recurrences (resp. 4.9 % (3/61) vs. 5.4 % (4/74) (p = 0.90)). This systematic review suggests that HIFU is an effective and safe treatment option for AWE. USgHIFU treatment led to reduced pain scores and lesion size, was free of major complications and had a pooled recurrence rate of 12.8 %. Compared to surgical excision pooled results showed no significant differences in pain scores, complications and recurrences after USgHIFU. However, many of the included studies had limitations in their methodological quality and therefore the results should be interpreted with caution. Well-structured high-quality randomized controlled trials comparing HIFU to standard care should be conducted to provide more conclusive evidence.

Caesarean-section scar endometriosis (CSSE): clinical and imaging fundamentals of an underestimated entity

Caesarean-section scar endometriosis (CSSE) is a form of extra-pelvic endometriosis developing through endometrial cell implantation anywhere along the route of a previous caesarean section (CS) surgery, including the skin, subcutaneous tissue, abdominal wall muscles, intraperitoneally, and the uterine scar itself. Synchronous intra-abdominal endometriosis is not a prerequisite. Given the rising prevalence of CS, CSSE may be underrepresented in the literature and occur more frequently than previously thought. Locating a painful soft-tissue mass-like lesion along the path of a previous CS scar is the most indicative sign that should initially alarm physicians towards suggesting CSSE, especially if symptoms are typical (cyclically reoccurring with menstruation). The detection of hyperintense (haemorrhagic) foci on T1 fat-saturated sequences will strongly support the diagnosis on magnetic resonance imaging (MRI), the most sensitive imaging method for CSSE assessment. A non-specific, contrast-enhancing, hypodense nodule with spiculate edges may be suggestive if the lesion was originally detected on computed tomography (CT). Although ultrasound is frequently the first imaging method used, the findings are non-specific; therefore, making it more useful for ruling out other differentials and for image-guided biopsy. In any case, histopathology provides the definitive diagnosis. Surgical excision is the mainstay of treatment; however, minimally invasive, percutaneous techniques have also been implemented successfully.

Safety and efficacy of microwave ablation for abdominal wall endometriosis: A retrospective study

Objectives

This retrospective study aimed to evaluate the safety and feasibility of ultrasound-guided microwave ablation in the treatment of abdominal wall endometriosis (AWE).

Background

AWE is a rare form of endometriosis that often results in cyclic abdominal pain. The current treatment algorithm for AWE is not well established. Microwave ablation technology is a promising new thermal ablation technique for treating AWE.

Methods

This was a retrospective study of nine women with pathologically proven endometriosis of the abdominal wall. All patients were treated with ultrasound-guided microwave ablation. Grey-scale and color Doppler flow ultrasonography, contrast-enhanced ultrasonography, and MRI were used to observe the lesions before and after treatment. The complications, pain relief, AWE lesion volume, and volume reduction rate were recorded 12 months after treatment to evaluate the treatment efficacy. Complications were classified according to the Common Terminology Criteria for Adverse Events and the Society of Interventional Radiology classification system.

Results

Contrast-enhanced ultrasound showed that all lesions underwent successful treatment with microwave ablation. The average initial nodule volume was 7.11 ± 5.75 cm³, which decreased significantly to 1.85 ± 1.02 cm³ at the 12-month follow-up with a mean volume reduction rate of 68.77 ± 12.50%. Periodic abdominal incision pain disappeared at 1 month after treatment in all nine patients. The adverse events and complications were Common Terminology Criteria for Adverse Events grade 1 or Society of Interventional Radiology classification grade A.

Conclusions

Ultrasound-guided microwave ablation is a safe and effective technique for the treatment of AWE, and further study is warranted.

Scar endometriosis: Looking beyond the diagnosis - A case series

Scar endometriosis usually affects the abdominal wall or the perineum. Virtually all cases are linked with some form of surgical manipulation. Although the clinical diagnosis of scar endometriosis may be straightforward with classical symptomology, imaging with ultrasound and MRI are important for the determination of its extent, which is imperative for adequate preoperative planning. In addition, assessment of perineal scar endometriosis also requires the identification of anal sphincter complex involvement, which can significantly impact the surgical approach. Radiology plays a vital role in its diagnosis in atypical clinical scenarios.

Contribution

This series of four cases describes the morphology and highlights the importance of imaging in the surgical management of scar endometriosis; three with abdominal wall involvement and one with the involvement of perineum.

Complications of Caesarean delivery part 2: Non-pregnant and pregnancy-related complications

INTRODUCTION

With the rise in Caesarean deliveries, complications related to the procedure are increasingly encountered. Sonography has an indispensable role in the assessment of these complications and is often the first-line investigation of choice.Topic description: Part 2 of this pictorial review summarises the non-pregnant and pregnancy-related complications of Caesarean deliveries.

DISCUSSION

Non-pregnant complications include Caesarean scar defects, scar endometriosis and malpositioned intrauterine devices. Complications related to future gestations include scar ectopic pregnancy, abnormal placentation and intrapartum uterine dehiscence or rupture. Key sonographic features of these conditions are illustrated. Pitfalls, mimics, limitations and indications for cross-sectional imaging are discussed.

CONCLUSION

Sound knowledge of the sonographic features of common non-pregnant and pregnancy-related complications of Caesarean delivery will facilitate accurate diagnosis, timely management and improved patient outcomes.

Feasibility and safety of percutaneous image-guided cryoablation of abdominal wall endometriosis

PURPOSE

To evaluate the feasibility and safety of percutaneous image-guided cryoablation of abdominal wall endometriosis (AWE).

MATERIALS AND METHODS

A retrospective review of percutaneous cryoablation (CT or MR) of AWE was performed from January 2018 to December 2020. Eighteen patients were identified from an internal percutaneous ablation database. Technical success, complications, and outcomes were analyzed according to standard nomenclature.

RESULTS

Patients comprised 18 females (mean age 36.9 years) who underwent 18 cryoablation procedures to treat 23 AWE deposits. Three of the 18 cases were performed under MR guidance, while the remaining 15 employed CT guidance. Technical success was achieved in all 18 cases (100%). Fifteen of 18 patients (83%) had biopsy proven AWE deposits prior to treatment. Hydrodisplacement was used to displace adjacent bowel, bladder, or neurovascular structures in 13/18 cases (72%). The mean number of probes used per case was 3. Sixteen of 23 (70%) of AWE deposits had imaging follow-up (median 85 days). Of the 16 lesions with imaging follow-up, 15 (94%) demonstrated no residual enhancement or T1 hyperintensity at the treatment site and 1 lesion (6%) demonstrated residual/progressive disease. At clinical follow-up, 13 of 14 (93%) patients reported improvement in AWE-related symptoms. Eleven patients had clinically documented pain scores before and after ablation and all demonstrated substantial symptomatic improvement. No society of interventional radiology (SIR) major complications were observed.

CONCLUSIONS

Percutaneous cryoablation of AWE is feasible with a favorable safety profile. Further longitudinal studies are needed to document durable response over time.

Endometriosis and Its Myriad Presentations: Magnetic Resonance Imaging-Based Pictorial Review

Endometriosis is a major cause of infertility and pain in females in the reproductive age group. It is a result of ectopic functional endometrial cells outside the uterus. It consists of a spectrum of findings from superficial to deep implants initiating a fibrotic response and resulting in adhesions. Diagnosis of endometriosis is based on clinical history, noninvasive and invasive techniques. The final diagnosis is based on laparoscopy with histopathological confirmation. Ultrasonography is the first line of investigation, followed by magnetic resonance imaging (MRI) in complex cases. MRI is a noninvasive, multiplanar technique that involves no radiation and provides excellent delineation of the disease process. As deep endometriosis has a similar low signal to adjacent normal organs, it can be easily overlooked by radiologists. They should be aware of the spectrum of diseases so as to provide a roadmap for the surgeons. A structured reporting system helps radiologists organize and standardize their reports.

Abdominal wall endometriosis: a case report

Abdominal wall endometriosis has an incidence of 0.3–1% of extrapelvic disease. Α 48-year-old female appeared in the emergency department with cellulitis in a lower midline incision. She had an endometrioma of the anterior abdominal wall removed 2 years ago. After 5 months, she underwent an open repair of an incisional hernia with a propylene mesh, which was unfortunately infected and removed 1 month later. Finally, in July 2019, she had her incisional hernia repaired with a biological mesh. Imaging modalities revealed a large mass below the umbilicus. Mass was punctured under ultrasound guidance. Cytology reported the recurrence of endometriosis. Pain and abdominal mass associating with menses were the two most typical symptoms. Wide local excision of the mass with at least 1 cm negative margins is the preferred treatment. Surgeons should maintain a high suspicion of the disease in reproductive women with circular pain, palpable abdominal mass and history of uterine-relating surgery.

Collagen I triggers directional migration, invasion and matrix remodeling of stroma cells in a 3D spheroid model of endometriosis

Endometriosis is a painful gynecological condition characterized by ectopic growth of endometrial cells. Little is known about its pathogenesis, which is partially due to a lack of suitable experimental models. Here, we use endometrial stromal (St-T1b), primary endometriotic stromal, epithelial endometriotic (12Z) and co-culture (1:1 St-T1b:12Z) spheroids to mimic the architecture of endometrium, and either collagen I or Matrigel to model ectopic locations. Stromal spheroids, but not single cells, assumed coordinated directional migration followed by matrix remodeling of collagen I on day 5 or 7, resembling ectopic lesions. While generally a higher area fold increase of spheroids occurred on collagen I compared to Matrigel, directional migration was not observed in co-culture or in 12Z cells. The fold increase in area on collagen I was significantly reduced by MMP inhibition in stromal but not 12Z cells. Inhibiting ROCK signalling responsible for actomyosin contraction increased the fold increase of area and metabolic activity compared to untreated controls on Matrigel. The number of protrusions emanating from 12Z spheroids on Matrigel was decreased by microRNA miR-200b and increased by miR-145. This study demonstrates that spheroid assay is a promising pre-clinical tool that can be used to evaluate small molecule drugs and microRNA-based therapeutics for endometriosis.

Clinico-pathological assessment of surgically removed abdominal wall endometriomas following cesarean section

BACKGROUND

Over the past few decades, the rate of Cesarean Section (CS) delivery has been rising rapidly and the prevalence of CS-associated complications including Abdominal Wall Endometriomas (AWE) increases with each additional operation. The aim of this study was to evaluate the clinical characteristics, histopathological diagnostic role and surgical management of post-CS AWE through a retrospective case review.

METHODS

We calculated the incidence of AWE and reviewed all the patients underwent surgical removal of Post-CS AWE during the period of 2012-2018 who were diagnosed, treated and followed up for 2-8 years at our tertiary hospital.

RESULTS

Thirty women with AWE were included. The main symptom in 2/3 of cases was cyclic pain and 4 cases (13.3%) had no symptoms. The mean interval between prior CS and appearance of symptoms was 55.2 months and the mean size of the excised mass was 42 mm. Free surgical margin was less than 9 mm in 9 patients (30%) but no recurrence was recorded among all the studied patients. Pre-operative FNAC diagnosis was performed for only 3 patients (10%) which helped in excluding other potential pathologies. The clinical-pathological agreement value for detection of the nature of the abdominal wall mass was 93.4%.

CONCLUSIONS

Patients with suspected AWE should undergo preoperative cytological biopsy to exclude alternative diagnosis. Wide surgical excision with margin of less than 1 cm could be accepted especially in case of weak abdominal wall. More studies on the post-CS complications; risks, prevention, early detection and proper management should be encouraged.

Giant Abdominal Wall Endometrioma: A Case Report

Endometriosis is defined as the presence of endometrial glands and stroma outside the uterine cavity. Endometriosis may involve a wide spectrum of anatomic locations, but it typically involves pelvic locations. We report the case of a 45-year-old woman who presented with a history of abdominal pain and swelling. She first noticed the swelling eight months prior to presentation, and it had gradually progressed in size. The patient reported that the swelling increased in size during menses. Physical examination revealed a well-defined firm mass to the right of the midline. The mass had a smooth surface but limited mobility after abdominal wall muscle contraction, suggesting an infiltration of the underlying muscular structures. The findings demonstrated by computed tomography of the abdomen confirmed the diagnosis of abdominal wall endometrioma. The patient underwent successful resection of the lesion with complete resolution of her symptoms.

Cases of abdominal wall endometriosis distinguished from soft tissue tumors: A report of three cases

Endometriosis is an estrogen-dependent inflammatory disease characterized by the presence of endometrium-like tissue in sites outside the uterine cavity. It affects 6-10% of women of reproductive age. Concerning abdominal wall endometriosis, it is particularly rare with a reported incidence of 0.03-3.5%. Abdominal wall endometriosis may be misdiagnosed as soft tissue tumors. Patients are often referred to an orthopedic department, although this is not familiar to orthopedic surgeons. In the present report, we describe three women with abdominal painful mass who had previously undergone Caesarean section. The masses were associated with their menstrual cycle and existed proximal to the Caesarean section surgical scar. Pelvic magnetic resonance imaging revealed isointense or hyperintense to muscle on both T1- and T2-weighted images. All patients were suspected of suffering from abdominal wall endometriosis, and were treated with complete surgical resection and developed no recurrence. The pathological findings confirmed endometrial gland and endometrial stroma features. Clinical symptoms and medical history play an important role in the diagnosis of abdominal wall endometriosis in addition to radiological examinations.

Extra-pelvic endometriosis: A review

BACKGROUND

Extra-pelvic endometriosis is a rare type of endometriosis, which occurs in a distant site from gynecological organs. The diagnosis of extra-pelvic endometriosis can be extremely challenging and may result in a delay in diagnosis. The main objective of this review was to characterize abdominal wall endometriosis (AWE) and thoracic endometriosis (TE).

METHODS

The authors performed a literature search to provide an overview of AWE and TE, which are the major types of extra-pelvic endometriosis.

MAIN FINDINGS

Abdominal wall endometriosis includes scar endometriosis secondary to the surgical wound and spontaneous AWE, most of which occur in the umbilicus or groin. Surgical treatment appeared to be effective for AWE. Case reports indicated that the diagnosis and treatment of catamenial pneumothorax or endometriosis-related pneumothorax (CP/ERP) are challenging, and a combination of surgery and postoperative hormonal therapy is essential. Further, catamenial hemoptysis (CH) can be adequately managed by hormonal treatment, unlike CP/ERP.

CONCLUSION

Evidence-based approaches to diagnosis and treatment of extra-pelvic endometriosis remain immature given the low prevalence and limited quality of research available in the literature. To gain a better understanding of extra-pelvic endometriosis, it would be advisable to develop a registry involving a multidisciplinary collaboration with gynecologists, general surgeons, and thoracic surgeons.

Encyclopedia of endometriosis: a pictorial rad-path review

Endometriosis affects approximately 10% of reproductive age women and represents a significant cause of pelvic pain and infertility. Unfortunately, the diagnosis of endometriosis is often delayed by years. Endometriosis may manifest as cystic lesions in the ovaries known as endometriomas. Superficial endometriosis is typically detected by laparoscopy along the pelvic peritoneum as these lesions tend to be difficult to detect by imaging. Deep infiltrative endometriosis may be detected by ultrasound, CT or MRI in classic locations within the pelvis, such as the posterior cul-de-sac and uterosacral ligaments. Endometriosis may also involve the thorax, gastrointestinal and urinary tracts, and locations such as the abdominal wall and abdominal organs. We present MRI and CT case examples, together with corresponding laparoscopic and histopathology images to enhance radiologists' understanding of this disease.

Percutaneous cryoablation of abdominal wall endometriosis: the Mayo Clinic approach

Abdominal wall endometriosis (AWE) is a rare form of endometriosis that often results in substantial pain and debility. The current treatment algorithm for AWE is not well established. The purpose of this review is to describe the Mayo Clinic experience with thermal ablation of symptomatic AWE as well as to review current imaging and interventional literature regarding the diagnosis and treatment of AWE.

Multimodality imaging and clinicopathologic assessment of abdominal wall endometriosis: knocking down the enigma

PURPOSE

To review the clinical, multimodality imaging, and pathologic characteristics of abdominal wall endometriosis (AWE), the most common type of extra-pelvic endometriosis.

METHODS

116 women with histopathologically confirmed extragenital endometriosis diagnosed between 2/2014 and 6/2017 were evaluated retrospectively. Of these, 26 (22.4%) were found to have AWE and 18/26 met inclusion criteria for imaging. Available imaging studies were re-reviewed by two expert radiologists. Data regarding clinical features, histopathologic findings, and management were collected through medical record review.

RESULTS

21 pathology-proven AWE deposits were identified by imaging in 18 women [mean age at diagnosis of 38.5 years (range 31-48)]. Prior C-section was present in 15/18 (83.3%) and pelvic endometriosis in 3/18 (16.7%) patients. Patients presented with abdominal pain in 14/18 (77.8%) cases, which was cyclical in 8/14; palpable mass in 12/18 (66.7%); fluid discharge in 2/18 (11.1%); and local skin discoloration in 2/18 (11.1%). Of the 21 lesions, 15 were evaluated with US, 10 with CT, and 5 with MRI. Mean lesion dimensions were 2.5 × 2.2 × 2.6 cm, and deposits were predominantly located at midline or left hemiabdomen [22/30 (73.3%)], were either stellate [15/30 (50%)] or round [15/30 (50%)] in shape, had ill-defined margins [21/30 (70%)], were heterogenous in appearance [27/30 (90%)], and involved both deep and superficial abdominal wall layers [17/30 (56.7%)]. On US, lesions were mainly isoechoic/hyperechoic [7/15 (46.7%)], and scarcely vascular [8/15 (53.3%)] with a peripheral vascular pattern [8/13 (61.5%)]. On CT, AWEs were hypervascular and homogeneous [8/10 (80%)], superiorly located to scar tissue, and on MRI lesions appeared hyperintense [4/5 (80%)] to muscle with T2 cystic and T1 hemorrhagic foci [4/5 (80%)]. In 23/27 (85.1%) original reports, there was at least one known mass prior to imaging; AWE was correctly diagnosed in only 7/23 (30.4%) cases. In those with no prior knowledge of a mass, the lesion was detected in 3/4 (75%), but AWE was only diagnosed in a single case. Median time between onset of symptoms and histopathology was 24.41 moths (IQR 15.18-47.33).

CONCLUSIONS

AWE is a challenging clinical entity frequently diagnosed with a significant delay and easily misinterpreted despite multimodality imaging. Familiarity with its radiologic features holds the potential for positively impacting diagnosis.

Scar Endometriosis Presenting as a Painful Abdominal Mass

Abdominal wall scar endometriosis occurs in 1%–2% of women following a cesarean section delivery. We report a case of a 36-year-old woman with scar endometriosis, presenting with an acute, painful abdominal wall mass. She underwent a cesarean section 8 years before presentation. She was admitted to the emergency room for physical examination of the abdomen, which revealed a palpable mass. Abdominal computed tomography (CT) revealed an ill-defined soft-tissue lesion over the left rectus abdominis muscle (abdominal scar). Surgical removal of the abdominal wall mass was performed with adequate clearance margins with a preoperative diagnosis of postcesarean scar endometriosis. Postcesarean scar endometriosis is a rare cause of an abdominal mass; however, when this condition presents acutely, it can be difficult to diagnose. In this case, careful analysis of the patient's history, CT images, and histopathological results together confirmed the diagnosis. Surgical excision was performed under general anesthesia while maintaining adequate clearance margins.

Abdominal wall mass suspected of endometriosis: clinical and pathologic features

Objective

To evaluate the clinical and pathological characteristics of lower anterior abdominal wall masses suspicious for endometriosis.

Methods

A retrospective review of 38 patients who underwent surgery for a lower anterior abdominal wall mass suspicious for endometriosis was performed. Those with skin and intraperitoneal masses, lipomas, hernias, and metastatic malignant masses were excluded. Patient age, body mass index, delivery history, dysmenorrhea, and mass size and location were analyzed.

Results

Thirty-seven (97.3%) patients had a relevant surgical history, including 35 (92.1%) with a history of cesarean section (C/S). Among the three patients with no history of C/S, 1 underwent total abdominal and another total laparoscopic hysterectomy, and 1 had no previous surgical history. The mean (±standard deviation) size of the abdominal masses was 3.2±1.2 cm. One patient developed a recurrent mass after excision of abdominal wall endometriosis. Trocar site endometrioma was found in one patient following total laparoscopic hysterectomy. According to the final pathology reports, endometriosis was found in 35 (92.1%) of patients. The remaining 3 patients (7.9%) had malignancy: adenocarcinoma, squamous cell carcinoma, and extra-gastrointestinal stromal tumor. Before surgery, only 3 patients (7.9%) underwent fine-needle aspiration biopsy of the masses, which were all postoperatively confirmed to be pathologically benign.

Conclusion

Although most abdominal wall masses in the present sample were endometriosis occurring at the scar site from a previous operation, 7.9% of patients ultimately exhibited malignancy. Therefore, all patients with suspected anterior wall endometriosis should undergo preoperative biopsy to identify the few that will have an alternative diagnosis.

Nonsurgical radiologic intervention for management of abdominal wall endometriosis: A systematic review and meta-analysis

Objective:

To describe reported outcomes of nonsurgical radiologic interventions for abdominal wall endometriosis in comparison with surgery where available.

Data sources:

A systematic search of Ovid Medline, Embase, PubMed, and Cochrane Controlled Register of Trials was performed from inception to January 2019 with no language restrictions.

Study eligibility criteria:

Studies were included if they evaluated a nonsurgical intervention in women with symptomatic abdominal wall endometriosis with both comparative and noncomparative study designs.

Study appraisal and synthesis methods:

Titles and abstracts were reviewed for relevance, and full-text articles were obtained and evaluated for inclusion, all in duplicate. Meta-analysis was performed when possible using a fixed effects model.

Results:

Of the 114 records reviewed, 16 full-text articles were assessed and 7 were included in analysis. The standard mean difference between pre- and post-intervention pain scores was similar between ultrasound-guided high-intensity focused ultrasound (USgHIFU) (−3.00; 95% confidence interval −3.34, −2.66) and cryoablation (−3.93; 95% confidence interval −5.73, −2.12). The mean percent decrease in lesion size following intervention was similar between USgHIFU (−61.38%; 95% confidence interval −78.64%, −44.11%), and cryoablation (−88.16%; 95% confidence interval −83.90%, −55.06%). When compared with surgical excision, mean length of stay was 2.78 days less in the nonsurgical intervention group (95% confidence interval −3.78, −1.79).

Conclusions:

Both USgHIFU and cryoablation are effective at reducing pain scores and lesion size in abdominal wall endometriosis. Mean length of stay was significantly less following a nonsurgical radiologic intervention for abdominal wall endometriosis compared with surgery. More studies are needed comparing complication and recurrence rates between nonsurgical radiologic interventions for abdominal wall endometriosis and surgery.

CT and MRI features of tumors and tumor-like lesions in the abdominal wall

Masses involving the abdominal wall are common in clinical practice and have many etiologies, including tumors and tumor-like lesions. Abdominal wall tumors include primary and secondary tumors, the former of which constitute a heterogeneous group of soft tissue tumors with their own unique spectrum. Tumor-like lesions, such as hernias, are more common and must be distinguished from true tumors. Medical imaging is valuable for discovering, diagnosing, and evaluating the extent of abdominal wall masses. With the increasing application of computed tomography (CT) and magnetic resonance imaging (MRI), determining a diagnosis or narrowing the differential diagnosis is often possible, thus facilitating effective management. In this article, we comprehensively review the spectrum of common abdominal wall masses and present the CT and MRI features of typical cases in our hospital. A systematic stepwise diagnostic approach is also proposed for clinical practice.

Abdominal wall endometriosis in a region distant to the caesarean section scar

Abdominal wall endometriosis (AWE) is a rare entity presenting as a painful lump with a cyclical pattern, associated with previous caesarean section (CS). AWE is typically located at the site of the CS scar. The diagnosis is challenging in the rare instance when AWE presents at a location distant to the CS scar. A 37-year-old patient presented to a general surgeon with a 2-year history of left-sided, periumbilical pain exacerbated during her menstrual periods. A 3 cm firm and tender nodule was noted clinically. Intraoperatively, the nodule involved the rectus muscle and infiltrated the peritoneum. Histology confirmed endometriosis, and the patient recovered uneventfully. The rarity of this clinical entity and the fact that AWE mostly presents to non-gynaecologists make the diagnosis challenging prolonging its physical and psychological morbidity. Thorough history-taking with emphasis on the pattern of pain and a previous history of CS should raise suspicion of AWE.

Abdominal Wall Endometrioma: A Diagnostic Enigma-A Case Report and Review of the Literature

Background

Abdominal wall endometriomas are quite uncommon. They are usually misdiagnosed by both the surgeon and the gynaecologist. Awareness of the details of this rare condition is therefore essential for prompt diagnosis and adequate treatment.

Introduction

Endometriosis though a condition commonly seen in the pelvic region can also occur at extrapelvic sites giving rise to a diagnostic dilemma. Abdominal wall endometrioma is one such complex variant of extrapelvic endometriosis with an incidence of less than 2% following gynaecologic operations.

Case Report

A case of abdominal wall endometrioma diagnosed clinically and treated by wide surgical resection is presented to highlight the importance of clinical evaluation in the diagnosis of this condition.

Discussion

The etiopathogenesis, presentation, investigations, and management are discussed briefly.

Conclusion

Clinical evaluation confirmed by supportive imaging is diagnostic. Wide local excision is the mainstay of treatment.

The Sonographic Spectrum of Pelvic Endometriosis: Pearls, Pitfalls, and Mimics

Endometriosis is a common disease of reproductive-age women that is often first encountered with ultrasound. Therefore, familiarity with the variety of manifestations of endometriosis is important for appropriate diagnosis and management. The aim of this article is to review the spectrum of appearance of pelvic endometriosis and to discuss potential mimics on ultrasound. Given that magnetic resonance imaging is an important problem-solving tool in female pelvic imaging, magnetic resonance imaging correlation is also provided.

Abdominal Wall Endometrioma: A Diagnostic Enigma-A Case Report and Review of the Literature

BACKGROUND

Abdominal wall endometriomas are quite uncommon. They are usually misdiagnosed by both the surgeon and the gynaecologist. Awareness of the details of this rare condition is therefore essential for prompt diagnosis and adequate treatment.

INTRODUCTION

Endometriosis though a condition commonly seen in the pelvic region can also occur at extrapelvic sites giving rise to a diagnostic dilemma. Abdominal wall endometrioma is one such complex variant of extrapelvic endometriosis with an incidence of less than 2% following gynaecologic operations.

CASE REPORT

A case of abdominal wall endometrioma diagnosed clinically and treated by wide surgical resection is presented to highlight the importance of clinical evaluation in the diagnosis of this condition.

DISCUSSION

The etiopathogenesis, presentation, investigations, and management are discussed briefly.

CONCLUSION

Clinical evaluation confirmed by supportive imaging is diagnostic. Wide local excision is the mainstay of treatment.

Vulvar endometriosis in the setting of a traumatic neuroma

Endometriosis is a rare documented source of vulvar pain. Extra-pelvic endometriosis and traumatic neuromas have been reported in individual cases as a source of pain in procedure-related scars following gynecologic surgery. However, the presence of vulvar endometriosis within a traumatic neuroma has not been documented before. We describe a case of a 42-year-old woman who presented with a chronic vulvar nodule that became swollen, painful, and pruritic 10 years following a Bartholin’s gland excision. Excision of the lesion was performed, and histological analysis revealed a traumatic neuroma with an embedded focus of endometriosis. The patient had complete resolution of her symptoms following excision. Endometriosis within a traumatic neuroma should be considered as a possible diagnosis in a post-operative scar that becomes painful, swollen, or pruritic in a cyclic nature. Surgical excision with routine and immunohistochemical pathologic analysis aids in the successful diagnosis and treatment.

Clinical analysis of high-intensity focussed ultrasound ablation for abdominal wall endometriosis: a 4-year experience at a specialty gynecological institution

OBJECTIVE

To evaluate the long-term clinical effect of high-intensity focussed ultrasound (HIFU) as a non-invasive modality for ablation of abdominal wall endometriosis (AWE) foci.

METHODS

All women who were diagnosed with cutaneous endometriosis and underwent HIFU ablation and 4-year follow-up were included. Patient symptoms, imaging performed, HIFU ablation, recurrence, lesion location, size and number were collected and analyzed.

RESULTS

A total of 51 women with 57 painful abdominal wall masses with a median volume of 4.00 cm³ and a mean age of 30.5±2.12 years were treated with HIFU. The main symptoms were a palpable painful abdominal mass (93%), protrusion of the skin (28.1%, 16) or lack of protrusion of the skin (71.9%, 41). Ultrasound was initially performed in 100% (51) of women, whereas 6% (3) required MRI examinations to distinguish the features and range of the masses. Ablation was performed with a median 300 s of sonication time, 40 min treatment time, 150 W of power and 41800 J of total energy to treat lesions that were a median volume of 3.83 cm³. No severe complications occurred, except in one patient with a first-degree skin burn, during the 48-month follow-up period. The pooled recurrence of cutaneous endometriosis occurred in 3.9% (2) of women.

CONCLUSION

The diagnosis of AWE should be confirmed with imaging of the lesion number, location, size and features before HIFU ablation. HIFU should be the first choice for the treatment of AWE as it is a non-invasive method, with high efficiency and safety and rapid postoperative recovery.

Urachal mucinous adenocarcinoma in the pelvic wall mimicking endometriosis

We report the case of a 30-year-old woman who complained of a painful palpable mass. Magnetic resonance imaging revealed an ill-defined mass approximately 8 cm in diameter with internal microcytic components. The mass diffusely involved the subcutaneous tissues, the muscles of the pelvic wall, and urinary bladder via a postoperative scar and resembled endometriosis. The histopathologic diagnosis was mucinous adenocarcinoma arisen from the urachal remnant. This is a very rare case of urachal adenocarcinoma arising mainly in the pelvic wall and mimicking endometriosis on MRI.

Skin Endometriosis at the Caesarean Section Scar: A Case Report and Review of the Literature

Cutaneous endometriosis is one of the rare gynecological conditions. Endometriosis is defined as the presence of endometrial glands and stroma outside the endometrial cavity. It commonly occurs in pelvic sites, such as the ovaries, cul-de-sac, bowel, or pelvic peritoneum. Endometriosis at the incisional scar is difficult to diagnose because of nonspecific symptoms. Usually, patients complain of pain at the site of the incision during menstruation. The main causes in most of the reported cases are obstetrical and gynecological surgeries. Endometrial tissues may be directly implanted in the scar during operation and, under hormonal stimulation, proliferate and form scar endometriosis. Diagnosis is usually made following histopathology. A wide excision is recommended to prevent recurrence. We report a case of a 33-year-old woman presenting with a brownish mass on the lateral aspect of the Pfannenstiel incision from a previous cesarean section scar. The symptoms appeared two years after her operation. The patient had cyclical pain and brownish discharge from the lesion during menstruation. Excision of the skin lesion with underlying subcutaneous tissue showed multiple, minute, firm hemorrhagic foci. Histopathology was performed and revealed a benign endometrial gland and stroma in the tissues, confirming the diagnosis of scar endometriosis. Cutaneous endometriosis is an uncommon gynecological condition and difficult to diagnose because of the nonspecific symptoms. Usually, it is confused with other dermatological and surgical diseases and delays the diagnosis and management. Surgical scar endometriosis following obstetric and gynecological procedures is more frequent recently due to an increase in the number of caesarian sections worldwide. Health care providers should suspect cutaneous endometriosis in any women with pain and a lump in the incisional scar after pelvic surgery.

Cesarean-Section Scar Endometrioma: A Case Report and Review of the Literature

Endometriomas can occur after any surgery where there is endometrial manipulation, and there are a number of reports of endometriomas developing in the abdominal wall at the site of the Pfannenstiel incision following Cesarean-section. Although this is ultimately a histopathologically-confirmed diagnosis, preoperative imaging including ultrasound, computed tomography, and magnetic resonance imaging may be helpful in the diagnosis and assessment. We report a pathology-confirmed case of Cesarean-section endometrioma with a classic, clinical presentation and imaging findings on computed tomography. A comprehensive literature review and discussion of the multi-modality imaging appearance of Cesarean-section endometrioma is also provided.

Surgical scar endometriosis: a series of 14 patients and brief review of literature

Background and aims

Endometriosis is a commonly encountered disorder in women of reproductive age, consisting of the presence of active ectopic endometrial tissue outside the endometrial cavity. Surgical scar endometriosis is a rare condition representing about 2% of all endometriosis cases. The purpose of this study was to assess the main characteristics, diagnostic tools and therapeutic options in abdominal wall endometriosis (AWE).

Methods

We have reviewed a series of fourteen cases with histopathological confirmation of AWE that were managed in our institution.

Results

The main characteristic of AWE were emphasized, showing that 78.57% of the patients had at least one previous caesarian section and that in only 57.14% of all cases an accurate diagnosis of AWE was established preoperatively.

Conclusion

A direct relationship between gynecological and obstetrical surgery and AWE is well established and as the caesarian section rates increase constantly, the awareness regarding AWE should also be increased.

Imaging of Female Pelvic Emergencies

Pelvic pain is a common complaint in female patients who present to the emergency department. Although encountered frequently, the path to a definitive diagnosis is not always a straightforward one, and imaging offers a valuable tool to aid in this diagnostic challenge. Radiologists must be familiar with the most common etiologies of female pelvic pain in the emergency setting, their imaging characteristics, and the best way to further evaluate challenging clinical presentations. This allows the radiologist to serve as a valuable asset to the treating physician, aiding in accurate diagnosis, and in guiding the course of treatment, all while ensuring the "Image Wisely" principle. A sonographic approach to female patients presenting to the emergency setting with pelvic pain has been presented in this article and some example entities along with their imaging findings have also been reviewed.

Abdominal wall endometriosis: differentiation from other masses using CT features

PURPOSE

To assess the utility of morphologic and quantitative CT features in differentiating abdominal wall endometriosis (AWE) from other masses of the abdominal wall.

METHODS

Retrospective IRB-approved study of 105 consecutive women from two institutions who underwent CT and biopsy/resection of abdominal wall masses. CTs were independently reviewed by two radiologists blinded to final histopathologic diagnoses. Associations between CT features and pathology were tested using Fisher's Exact Test. Sensitivity, specificity, positive, and negative predictive values were calculated. P values were adjusted for multiple variable testing.

RESULTS

24.8% (26/105) of patients had histologically proven abdominal wall endometriosis. The other most common diagnoses included adenocarcinoma NOS (21%; 22/105), desmoid (14.3%; 15/105), and leiomyosarcoma (8.6%; 9/105). CT features significantly associated with endometriosis for both readers were location below the umbilicus (P = 0.0188), homogeneous density (P = 0.0188), and presence of linear infiltration irradiating peripherally from a central soft tissue nodule (i.e., "gorgon" sign) (P < 0.0001). The highest combined sensitivity (0.69, 95% CI: 0.48-0.86) and specificity (0.97, 95% CI: 0.91-1.00) for both readers occurred for patients having all three of these features present. Border type (P = 0.0199) was only significant for R2, peritoneal extension (P = 0.0188) was only significantly for R1, and the remainder of features were insignificant (P = 0.06-60). There was overlap in Hounsfield units on non-contrast CT (N = 26) between AWE (median: 45HU, range: 39-54) and other abdominal wall masses (median: 38.5HU, range: 15-58).

CONCLUSION

CT features are helpful in differentiating AWE from other abdominal wall soft tissue masses. Such differentiation may assist decisions regarding possible biopsy and treatment planning.

Mid-term outcomes after percutaneous cryoablation of symptomatic abdominal wall endometriosis: comparison with surgery alone in a single institution

OBJECTIVES

To compare the outcomes of percutaneous image-guided cryoablation of symptomatic abdominal wall endometriosis (AWE) versus surgery alone.

METHODS

From 2004 to 2016, cryoablation or surgery alone was performed under local (n = 5) or general anaesthesia (n = 15) for AWE in a single institution in 7 (mean age, 36.1 years) and 13 (mean age, 31.9 years) patients, respectively. Fifteen lesions were treated by cryoablation (mean size, 2.3 cm; range, 0.5-7 cm) and 16 by surgery (2.5 cm; 1.1-3.4 cm). Tolerance, efficacy and patient and procedural characteristics were compared.

RESULTS

Median follow-up was 22.5 (range, 6-42) months after cryoablation and 54 (14-149) after surgery. The median procedure and hospitalisation durations were 41.5 min (24-66) and 0.8 days (0-1) after cryoablation, and 73.5 min (35-160) and 2.8 days (1-12 days) after surgery (both P = 0.01). Three patients (23.1%) had severe complications and nine aesthetic sequels (69.2%) after surgery, none after cryoablation (P = 0.05). The median 12- and 24-month symptom free-survival rates were 100% and 66.7% (95% CI, 5.4; 94.5) after cryoablation and 92% (55.3; 98.9) after surgery at both time points (P = 0.45).

CONCLUSIONS

Cryoablation presents similar effectiveness to surgery alone for local control of AWE while reducing hospitalisation duration and complications. Any aesthetic sequels were associated with the cryoablation treatment.

KEY POINTS

• Hospitalisation is shorter after cryoablation than after surgery of abdominal wall endometriosis. • A significantly lower rate of complications is observed after cryoablation compared to surgery. • Cryoablation of abdominal wall endometriosis presents similar effectiveness to surgery alone. • A significant reduction of pain is observed 6 months after treatment. • A significant reduction of abdominal wall endometriosis is observed at 6 months.

Diagnosis and Management of Abdominal Wall Endometriosis: A Systematic Review and Clinical Recommendations

Importance

Abdominal wall endometriosis (AWE) is a rare but easily treated cause of pain in women, especially those who have undergone cesarean deliveries.

Objective

This article reviews the diagnosis and management of AWE, a condition that generally develops after surgery but may arise spontaneously. We present a systematic review of the existing literature on AWE, as well as our clinical recommendations for medical and surgical management.

Evidence Acquisition

We searched PubMed and other databases using the search criteria "abdominal wall endometriosis," "abdominal wall endometriomas," and "abdominal wall mass." The references of those articles were then reviewed, and additional publications were evaluated.

Results

Many case reports and case series have been published describing AWE. The overall quality of evidence is poor due to the lack of prospective studies and heterogeneous descriptions of AWE lesions and treatment options. Based on the available literature, it appears that AWE may arise spontaneously but is generally associated with prior pelvic surgery. Abdominal wall endometriosis can be diagnosed with a careful history and physical examination. Imaging including ultrasound and magnetic resonance imaging can assist with localization of the lesions, and aid in surgical excision and management. Lesions that have been removed in their entirety are unlikely to reoccur.

Conclusions and Relevance

Although limited, the body of literature describing management of AWE suggests that it can be successfully treated in most patients with careful surgical planning.

Risk Factors, Clinical Presentation, and Outcomes for Abdominal Wall Endometriosis

STUDY OBJECTIVE

To evaluate the risk factors, presentation, and outcomes in cases of abdominal wall endometriosis.

DESIGN

A case-control study (Canadian Task Force classification II-2).

SETTING

An academic medical center.

PATIENTS

A total of 102 (34 cases and 68 controls) were included.

INTERVENTIONS

Surgical resection of abdominal wall endometriosis.

MEASUREMENTS AND MAIN RESULTS

Cases underwent surgical excision for abdominal wall endometriosis at Mayo Clinic from January 1, 2000, through December 31, 2013. For each case, 2 controls were randomly selected from a list of women who had surgery in the same year with minimal (American Society for Reproductive Medicine stage I-II) endometriosis. A chart review was completed for variables of interest. Regression models were used to identify independent risk factors associated with abdominal wall endometriosis.

RESULTS

In 14 years, 2539 women had surgery for endometriosis at Mayo Clinic. Of these, only 34 (1.34%) had abdominal wall endometriosis. The mean age was 35.2 ± 5.9 years, and the median parity was 2 (range, 0-5). Clinical examination diagnosed abdominal wall endometriosis in 41% of cases, with the cesarean delivery scar being the most common site (59%). There was a strong correlation between the size of the lesion on clinical examination compared with the size of the pathology specimen (r² = 0.74, p < .001). When compared with controls, cases had significantly higher parity and body mass index, more cyclic localized abdominal pain, less dysmenorrhea, longer duration from the start of symptoms to surgery, and more gynecologic surgeries for symptoms without cure. In the final multivariable model, cyclic localized abdominal pain, absence of dysmenorrhea, and previous laparotomy were independently associated with abdominal wall endometriosis with adjusted odds ratios of 10.6 (95% CI 1.85-104.4, p < .001), 12.4 (95% CI 1.64-147.1, p < .001), and 70.1 (95% CI 14.8-597.7, p < .001), respectively, with an area under the curve for the receiver operating characteristic of 0.94 (95% CI, 0.87-0.98). After excision of the disease, repeat surgery was needed in 2 (5.9%) patients with a median time to recurrence of 50.5 (range, 36-65) months.

CONCLUSIONS

Abdominal wall endometriosis is a rare but unique form of endometriosis. Careful history and clinical examination can provide accurate diagnosis and avoid unnecessary delay before surgical intervention. Localized cyclic abdominal pain with the absence of dysmenorrhea and a history of prior laparotomy are independent risk factors with very high accuracy for diagnosis.

Symptomatology and Surgical Perspective of Scar Endometriosis: A Case Series of 16 Women

AIM

The prevalence of scar endometriosis is increasing with the increasing caesarean deliveries and laparoscopic procedures done for pelvic endometriosis. To analyse the symptomatology and surgical perspective of scar endometriosis.

MATERIALS AND METHODS

Retrospective review of 16 women who underwent surgery for scar endometriosis in the period of 4 years in Amrita institute of medical sciences.

RESULTS

Mean age of the patients is 35.19 years. Mean interval from the index surgery to the presentation is 4.56 years. Mean size of the swelling is 2.84 cm. In 68.8% of the patients, caesarean section was the inciting surgery. 18.7% had port site endometriosis. Cyclical pain and swelling at the scar site was present in 93.8% of the women. 18.9% had concurrent pelvic endometriosis. All women had involvement of the subcutaneous tissue followed by 11 women with the involvement of rectus sheath. There was no recurrence of the lesion in the operated patients in the mean follow-up period of 11.91 months.

CONCLUSION

In all women presenting with cyclical scar site pain and swelling, scar endometriosis should be considered. It commonly follows caesarean section and laparoscopic surgeries done for endometriosis. Wide local excision with or without reconstruction is the method of choice for this condition. Role of tumescent solution during surgery and postoperative medical management to reduce recurrence needs further prospective studies.

Beyond hernias: a multimodality review of abdominal wall pathology

The diagnosis of abdominal wall pathology is often obvious on clinical physical examination; however, multimodality imaging often yields incidental, and occasionally important, findings aiding in assessing the overall clinical picture. While various hernias are common, there are numerous other causes of abdominal wall pathology. Knowledge of these entities is crucial to avoid misinterpretation and assure proper radiological judgment.

Endometriosis of Extra-Abdominal Soft Tissues

While endometriosis, defined as the presence of endometrial tissue in extrauterine sites, is most frequently encountered within the peritoneal cavity, a small but significant proportion of cases occur at extra-abdominal soft tissue sites, particularly in relation to previous abdominal surgery. We reviewed the cases of endometriosis of soft tissue sites seen at a tertiary soft tissue center. All cases of extra-abdominal soft tissue endometriosis diagnosed at this institution over a 13-year period were reviewed, and clinical and pathologic findings were recorded. Forty-five patients had diagnoses of soft tissue endometriosis and there were 34 diagnostic biopsies and 26 surgical excision specimens. All but 1 case were abdominal wall lesions, with 1 located in the upper arm. A total of 33 patients presented with lesions in scars of previous operations (31 in Pfannenstiel incisions for Caesarean sections, presenting with a median interval of 6 years (range 1-16 years) following surgery). The lesions ranged in size from 1 to 8 cm (median 3.5 cm). One case showed decidualized stroma with trophoblast cells, while 2 had secondary adenocarcinoma arising from endometriosis. Eighteen cases were tested for β-catenin expression immunohistochemically, of which 5 showed at least focal nuclear positivity in the surrounding fibrous tissue (although not within glands or stroma). Soft tissue endometriosis is seen most commonly in surgical scars, particularly following Caesarean sections. Spontaneous endometriosis also most commonly occurs in the abdominal wall, although can occur exceptionally at unusual sites, such as extremities. Secondary changes, including carcinomas, can arise from endometriosis. The differential diagnosis of these lesions includes fibromatosis, which may be erroneously diagnosed on small, nonrepresentative core biopsy specimens.