Appearance of abdominal wall endometriosis on MR imaging

Endometriosis, a common but enigmatic disease with many faces: current concept of pathophysiology, and diagnostic strategy

Endometriosis is a benign, common, but controversial disease due to its enigmatic etiopathogenesis and biological behavior. Recent studies suggest multiple genetic, and environmental factors may affect its onset and development. Genomic analysis revealed the presence of cancer-associated gene mutations, which may reflect the neoplastic aspect of endometriosis. The management has changed dramatically with the development of fertility-preserving, minimally invasive therapies. Diagnostic strategies based on these recent basic and clinical findings are reviewed. With a focus on the presentation of clinical cases, we discuss the imaging manifestations of endometriomas, deep endometriosis, less common site and rare site endometriosis, various complications, endometriosis-associated tumor-like lesions, and malignant transformation, with pathophysiologic conditions.

Percutaneous cryoablation of abdominal wall endometriosis: An analysis of 38 patients

PURPOSE

The purpose of this study was to evaluate the efficacy of percutaneous cryoablation in the treatment of abdominal wall endometriosis (AWE) nodules.

MATERIALS AND METHODS

Thirty-eight women treated for symptomatic AWE nodules with percutaneous cryoablation under ultrasound and computed tomography (CT) guidance between May 2020 and July 2023 were retrospectively included. Pain was estimated using visual analog scale (VAS) and assessed at baseline, three months, six months, and 12 months after percutaneous cryoablation. Baseline VAS score, volume of AWE nodule and magnetic resonance imaging (MRI) features of AWE nodules were compared to those obtained after percutaneous cryoablation. Major complications, if any, were noted.

RESULTS

Thirty-eight women with a median age of 35.5 years (interquartile range [IQR]: 32, 39; range: 24-48 years) and a total of 60 AWE nodules were treated. Percutaneous cryoablation was performed under local or regional anesthesia in 30 women (30/38; 79%). Significant decreases between initial median VAS score (7; IQR: 6, 8; range: 3-10) and median VAS score after treatment at three months (0; IQR: 0, 5; range; 0-8) (P < 0.001), six months (0; IQR: 0, 1; range; 0-10) (P < 0.001) and 12 months (0; IQR: 0, 2; range: 0-7) (P < 0.001) were observed. Percutaneous cryoablation resulted in effective pain relief in 31 out of 38 women (82%) at six months and 15 out of 18 women (83%) at 12 months. Contrast-enhanced MRI at six-month follow-up showed a significant decrease in the volume of AWE nodules and the absence of AWE nodule enhancement after treatment by comparison with baseline MRI (P < 0.001). No major complications were reported.

CONCLUSION

Percutaneous cryoablation is an effective, minimally invasive intervention for the treatment of AWE nodules that conveys minimal or no morbidity.

Resolution of Pain after Percutaneous Image-Guided Cryoablation of Extraperitoneal Endometriosis

PURPOSE

To retrospectively evaluate the relief of pain after percutaneous image-guided cryoablation of symptomatic extraperitoneal endometriosis (EE).

MATERIAL AND METHODS

From 2017 to 2022, cryoablation of EE was performed at a single institution on a total of 47 lesions in 42 consecutive patients (median age, 37 years; interquartile range [IQR], 33-39.5 years). Patient and procedural characteristics were reviewed retrospectively. Tolerance and outcomes in terms of pain and patient satisfaction were evaluated.

RESULTS

The median follow-up duration was 13.5 months (IQR, 1.1-37.7 months) after cryoablation. The median pain-free survival rate was 93.8% (95% confidence interval [CI], 77.3-98.4) at 6 months and 82.7% (95% CI, 58.8-93.5) after 12 months. Pain decreased from a median of 8/10 (IQR, 7-9) on the visual analog scale to 0/10 (IQR, 0-1) at the last follow-up (P < .0001). The median Patient Global Impression of Change score recorded at the last follow-up was 1/7 (IQR, 1-2). The efficacy rate of cryoablation to avoid secondary surgery was 92.8% (39/42) per patient and 93.6% (44/47) per nodule treated. Four patients (9.5%, 4/42) experienced an adverse event in the days following the procedure, and 1 patient (2%) experienced a severe adverse event.

CONCLUSIONS

Percutaneous cryoablation is safe and effective in significantly reducing pain and obtaining local control of EE.

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.

Surgical Scar Endometriosis: An Emerging Enigma

Introduction Surgical scar endometriosis is a subtype of extra-pelvic endometriosis that is characterized by the formation of endometrial tissue near the incision site in patients who have previously undergone surgery. In recent times, with the increasing trend in Caesarean sections, the incidence of surgical scar endometriosis has also emerged. This study aims to describe the clinical characteristics and management of surgical scar endometriosis. Methodology We conducted this cross-sectional, observational study over eight years (2015-2022) in a tertiary care centre in Madurai district, Tamil Nadu, India. We conducted this study after acquiring an ethical certificate from the institutional ethics committee (IEC No. VMCIEC/22/2018). In this study, we sampled all women (n = 32) with a pathological diagnosis of scar endometriosis during the study period from hospital records (universal sampling). We searched the data for both general characteristics and lesion characteristics of the patients. The general characteristics include age, body mass index (BMI), parity, mode of delivery, symptoms, and imaging by ultrasound. We have recorded the lesion characteristics of the patient, including location and size of scar endometriosis, layers involved in scar endometriosis, and surgical technique from surgical notes written in the case sheet. The minimum sample size required for this study was 31 study subjects. We entered the data into Excel (Microsoft, Redmond, WA, USA) and analyzed it in SPSS version 21 (IBM Corp., Armonk, NY, USA). We expressed the quantitative variables in terms of mean and standard deviation and the qualitative variables in terms of frequency and percentage. Results The mean age of the study participants was 34 years (range 23-55 years). In our study, 29 patients (90.6%) were multi-para, and only three (9.4%) were nullipara. Among 29 parous women, the majority (25, or 77.7%) had delivered by Caesarean section, while only four (12.5%) delivered by normal vaginal delivery. The surgical procedures preceding the scar endometriosis were predominantly obstetric procedures (87.4%), out of which 25 patients underwent a Caesarean section and only three underwent an episiotomy. The most common presenting symptom of scar endometriosis in our study was cyclical pain in the scar site (90.4%), followed by swelling (81.25%). In 62.5% of patients, the duration between the presentation of surgical scar endometriosis and surgical intervention was greater than one year. Subcutaneous tissue (90.6%) was the most commonly involved layer in surgical scar endometriosis, followed by the rectus sheath (86.2%). The surgical procedure done for scar endometriosis was wide local excision in 78% of patients, and the remaining 22% of patients had wide local excision with mesh repair. Conclusion Cesarean section is an obvious risk factor for surgical scar endometriosis. Clinicians should have a high index of suspicion for surgical scar endometriosis in women presenting with cyclic pain at the scar site. Ultrasound is accurate in diagnosing scar endometriosis. Surgical management by wide local excision with a clear margin with or without mesh repair is the treatment of choice.

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.

The Benign Side of the Abdominal Wall: A Pictorial Review of Non-Neoplastic Diseases

The abdominal wall is the location of a wide spectrum of pathological conditions, from benign to malignant ones. Imaging is often recommended for the evaluation of known palpable abdominal masses. However, abdominal wall pathologies are often incidentally discovered and represent a clinical and diagnostic challenge. Knowledge of the possible etiologies and complications, combined with clinical history and laboratory findings, is crucial for the correct management of these conditions. Specific imaging clues can help the radiologist narrow the differential diagnosis and distinguish between malignant and benign processes. In this pictorial review, we will focus on the non-neoplastic benign masses and processes that can be encountered on the abdominal wall on cross-sectional imaging, with a particular focus on their management. Distinctive sonographic imaging clues, compared with computed tomography (CT) and magnetic resonance (MR) findings will be highlighted, together with clinical and practical tips for reaching the diagnosis and guiding patient management, to provide a complete diagnostic guide for the radiologist.

Ultrasound-guided microwave ablation for symptomatic abdominal wall endometriosis and treatment response evaluation with contrast-enhanced imaging: The first experience

INTRODUCTION: Abdominal wall endometriosis (AWE) is a relatively uncommon condition associated with diagnostic and therapeutic difficulties among all the extra pelvic endometriosis. The main therapies include surgery and oral contraceptive administration. Percutaneous cryoablation and high intensity focused ultrasound (HIFU) are also proven to be valid alternatives. Microwave ablation (MWA) as one of the thermal ablation methods has not been applied in the treatment of AWE yet. Herein the feasibility of ultrasound (US) –guided MWA for AWE was explored and treatment response evaluation was carried out using contrast-enhanced imaging. METHODS: Three consecutive patients who underwent US-guided MWA for AWE with typical symptoms were included in the retrospective study. US, magnetic resonance imaging (MRI), laboratory tests, and US-guided core-needle biopsy were conducted for pre-treatment assessment and ruling out malignancy. The interventional procedure was carried out under local anesthesia with the microwave system and the output power was 60w. Post-treatment contrast-enhanced ultrasound (CEUS) was performed to evaluate the instant treatment response. The follow-up intervals were 1 month, 6 months, and 12 months after treatment. The clinical symptoms and condition of AWE lesions were recorded in each follow-up. RESULTS: The MWA procedure was completed in all the patients with no blood perfusion inside each lesion by instant CEUS after treatment. The mean ablation time was 687 seconds (s) for a single patient (ranged from 660s to 742s). Clinical symptoms were relieved evidently at the end of the follow-up. The pain according to the visual analogue scale (VAS) decreased from 4–6 before treatment to 0–2 after treatment. Mild to moderate complications included slightly abdominal pain and fat liquefaction occurred. In terms of technical outcomes, the volume of all six lesions reduced in different degrees at the end of follow-up (ranged: 16.6% to 100% ). CONCLUSION: US-guided MWA may be a feasible and promising approach for symptomatic AWE.

Exploring the Diagnostic Performance of Magnetic Resonance Imaging in Ultrasound-Guided High-Intensity Focused Ultrasound Ablation for Abdominal Wall Endometriosis

OBJECTIVE

This study aimed to explore the clinical value of magnetic resonance imaging (MRI) combined with ultrasound-guided high-intensity focused ultrasound (USg-HIFU) for the diagnosis and treatment of abdominal wall endometriosis (AWE).

METHODS

Magnetic resonance imaging was performed before and after USg-HIFU. Information on clinical characteristics of patients, MRI characteristics of lesions, and treatment outcomes were collected. Thirty AWE lesions in 29 patients were examined before HIFU treatment, while 27 patients were examined after treatment. The results of MRI and color doppler ultrasound before surgery, as well as the volume and the apparent diffusion coefficient (ADC) values of the lesions before and after USg-HIFU treatment were compared. We also observed the clinical symptoms remission, recurrence, and ablation rates of the lesions in follow-up after HIFU treatment.

RESULTS

The locations of the 30 AWE lesions were identified by MRI before USg-HIFU treatment. Their sizes appeared larger on MRI than ultrasound (P < 0.05). A total of 27 lesions were evaluated by MRI after USg-HIFU treatment, of which 92.6% (25/27) lesions were of high or slightly high signal intensity on T1-weighted images, and 77.8% (21/27) lesions were of mixed signal intensity on T2-weighted images. The mean ADC values of AWE lesions were 1.47 (1.20-1.59) × 10-3mm2/s and 1.86 (1.61-2.12) × 10-3mm2/s for pre-and post-HIFU treatment (P < 0.05). Patients with higher ablation rates (>50%) had a higher complete/partial remission rate than those with lower ablation rates (<50%), and had a lower recurrence rate (P < 0.05).

CONCLUSION

MRI is a useful tool for identifying the location, size, and concurrent changes of AWE before and after USg-HIFU treatment, which is beneficial for follow-up monitoring and defining treatment efficacy.

MRI in the Diagnosis of Endometriosis and Related Diseases

Endometriosis, a common chronic inflammatory disease in female of reproductive age, is closely related to patient symptoms and fertility. Because of its high contrast resolution and objectivity, MRI can contribute to the early and accurate diagnosis of ovarian endometriotic cysts and deeply infiltrating endometriosis without the need for any invasive procedure or radiation exposure. The ovaries, which are the most frequent site of endometriosis, can be afflicted by multiple related conditions and diseases. For the diagnosis of deeply infiltrating endometriosis and secondary adhesions among pelvic organs, fibrosis around the ectopic endometrial gland is usually found as a T2 hypointense lesion. This review summarizes the MRI findings obtained for ovarian endometriotic cysts and their physiologically and pathologically related conditions. This article also includes the key imaging findings of deeply infiltrating endometriosis.

Magnetic Resonance Imaging in the Evaluation of Female Infertility

Pelvic MRI plays an important adjunctive role in the clinical workup of female infertility. Hysterosalpingography is the first line imaging modality in evaluation of female infertility, and hysterosalpingo-contrast sonography can also be used to evaluate both the uterine cavity and fallopian tubes. Pelvic MRI can be helpful in the workup of female infertility, particularly in cases of Mullerian duct anomalies, fibroids, adenomyosis, endometriosis, and tubal disease. These conditions and their appearance on imaging will be reviewed in this article.

Abdominal wall endometriomas. Should the approach vary based on its relationship to the fascia? A case report and review of the literature

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Abdominal wall endometriomas are rare but not uncommon.

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Needle biopsy should be attempted before excision to rule out malignancy.

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Malignant degeneration should always be considered in abdominal wall endometriomas.

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Abdominal wall endometriomas involving significant muscle and fascia should be considered for nonsurgical treatment.

Introduction

Abdominal wall endometrioma (AWE) is a rare encountered condition with a prevalence of 1–2%. Multiple diagnostic and treatment modalities are available; however, no clear guidelines exist. On occasions muscle and fascia excision might be necessary to achieve a clear margin. To avoid mesh complications, we believe the treatment should depend on tumor location in relation to the abdominal wall fascia. As far as we know this approach has not been previously discussed.

Presentation

A 29-year old female with a surgical history of 3 C-sections presented to us with 6 months of cyclical abdominal pain in the left lower quadrant. Imaging studies confirmed the presence of a mass overlying the left lower rectus abdominis muscle. After imaging studies, the mass was surgically excised. Pathology confirmed a benign endometrioma.

Discussion

Unfortunately, the surgical literature has not established a consensus on the best approach for diagnosis and management of this condition. The purpose of this report is to not only to present another case of this rare phenomenon, but to address the need for guidelines and review the current diagnostic and treatment available options. We also attempt to increase the awareness of this condition, it’s unlikely malignant degeneration and potential morbidity of surgical excision.

Conclusion

Surgical excision remains the standard of care for AWEs. In those patients where the fascia and muscle must be excised, we recommend less invasive modalities to avoid mesh complications. The need for guidelines remains.

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.

Pelvic MRI in the diagnosis and staging of pelvic endometriosis: added value of structured reporting and expertise

PURPOSE

To compare the diagnostic characteristics of routine-read (RR), structured-reported read (SR), and structured expert-read pelvic (SER) MRI for staging of pelvic endometriosis in a tertiary care academic center.

METHODS

Of 530 patients with endometriosis (2013-2018), 59/530 (11.1%) were staged surgically and underwent pelvic MRI. Radiology reports were considered RR; MRI studies were independently reassessed by SR and SER. Involvement was recorded by compartment [anterior (AC), middle (MC), posterior (PC), adnexal (AX), and other (OC)]. Diagnostic discrepancy between review methods was assessed with McNemar's test. Interobserver agreement was assessed using Cohen's unweighted kappa.

RESULTS

Of 295 compartments in 59 women (mean age = 38.8 years; range 20-69), 147/295 (49.8%) had confirmed endometriosis. Overall sensitivity: RR = 42.9%; SR = 86.4%; SER = 74.2%. SR's increased sensitivity was significant for PC (p < 0.001), MC (p < 0.001), AC (p = 0.001), AX (p = 0.038). Higher sensitivity by SER was significant for PC (p < 0.001), MC (p = 0.004) and AC (p < 0.001), but not AX (p > 0.05). Overall specificity: RR = 95.3%; SR = 45.9%; SER = 81.8%. SER specificity was no different than RR for PC or AX (p > 0.5). RR sensitivity relied heavily on detection of AX involvement, whereas SR and SER showed additional sites of disease while maintaining comparable specificity for SER. Overall agreement between SR and SER was fair [k = 0.342 (95% CI 0.25, 0.44)].

CONCLUSIONS

Even at a tertiary care academic center, SER outperforms both SR and RR in the assessment of pelvic endometriosis. Although lack of expertise may negatively impact specificity, use of structured reporting is significantly more sensitive than RR. Therefore, its use can be of assistance in surgical planning and patient counseling.

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.

Imaging of Abdominal Wall Masses, Masslike Lesions, and Diffuse Processes

Abdominal wall masses, masslike lesions, and diffuse processes are common and often incidental findings at cross-sectional imaging. Distinguishing among these types of masses on the basis of imaging features alone can be challenging. The authors present a diagnostic algorithm that may help in distinguishing different types of abdominal wall masses accurately. Hernias may mimic discrete masses at clinical examination, and imaging is often ordered for evaluation of a possible abdominal wall mass. Once a discrete mass is confirmed to be present, the next step is to determine if it is a fat-containing, cystic, or solid mass. The most common fat-containing masses are lipomas. Fluid or cystic masses include postoperative abscesses, seromas, and rectus sheath hematomas. Solid masses are the most common abdominal wall masses and include desmoid tumors, sarcomas, endometriomas, and metastases. Multiple masses and other diffuse abdominal wall processes are often manifestations of an underlying condition or insult. The most frequently found diffuse processes are multiple injection granulomas from administration of subcutaneous medication. This article offers an algorithmic approach to characterizing abdominal wall masses on the basis of their composition and reviews abdominal wall diffuse processes. Online supplemental material is available for this article. ^©RSNA, 2020.

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.

Imaging findings of cesarean delivery complications: cesarean scar disease and much more

In the last years, there has been a significant increase in the number of cesarean deliveries and, with it, of the number of complications following the procedure. They can be divided into early and late ones. We will illustrate herein the most common complications following cesarean section to help radiologists to recognize them. To familiarize with these various pathologic conditions is crucial to alert referring clinicians for a prompt and appropriate maternal and fetal management. Special attention will be given to the cesarean scar defect (CSD), the most common but also the most unknown of such conditions. Although often asymptomatic, a severe CSD represents a predisposing factor for subsequent complications especially in future pregnancies.

Abdominal wall endometriosis: An 11-year retrospective observational cohort study

Objective

The objective of this study was to review the records of patients with excised abdominal wall endometriosis (AWE) to determine patient characteristics, diagnostic methods, presence of concurrent pelvic endometriosis and type of surgery.

Study design

Medical records from an 11-year period were searched to identify histologically confirmed AWE cases. Descriptive data were collected and analyzed. Two subgroups were differentiated: isolated AWE and pelvic endometriosis-associated AWE.

Results

Thirty-five women with AWE were included. The most common symptom was cyclic abdominal or parietal pain (68.6%); 17.1% of the women had no symptoms. Twenty-nine women (82.8%) had a history of gynecological or obstetrical surgery, most commonly cesarean section (CS). The mean interval between prior surgery and appearance of symptoms was 5.3 years. Six women (17.1%) had no prior surgery; all six presented with umbilical nodules, nulliparity and confirmed mild to severe pelvic endometriosis. Among all patients, 34.3% had concurrent pelvic endometriosis, 40% presented with isolated AWE and 25.7% had no pelvic exploration. Women with concurrent pelvic endometriosis had significantly lower parity, smaller nodule size and a higher likelihood of umbilical location than those with isolated AWE (p < 0.05). A history of CS was more commonly found in women with isolated AWE. The overall recurrence rate over the study period was 11.4%, with a mean follow-up period of 5.2 years.

Conclusions

AWE is an uncommon condition associated with long diagnostic and therapeutic delays. In patients with umbilical AWE and no surgical history, pelvic endometriosis is commonly present and should be highly suspected.

Mixed endometrioid and clear cell carcinoma arising from laparoscopic trocar site endometriosis

Laparoscopic port site endometriosis is less common in abdominal wall endometriosis, and malignant transformation of abdominal wall endometriosis is rare. We reported a case of mixed endometrioid and clear cell carcinoma arising from port site endometriosis. The patient was a 49-year-old woman with a history of laparoscopic excision of ovarian endometrioma. Physical examination revealed a subcutaneous solid tumor around the laparoscopic surgical scar. Imaging showed a suspicious malignancy. She underwent radical marginal resection of the abdominal wall tumor, flap reconstruction of the abdominal wall, hysterectomy, bilateral salpingo-oophorectomy and omental biopsy. Histological examination revealed mixed endometrioid and clear cell carcinoma. Computed tomography scan showed no evidence of recurrence after six cycles of chemotherapy. This is the first case of malignant transformation from laparoscopic trocar site endometriosis.

Diffusion-weighted imaging in hemorrhagic abdominal and pelvic lesions: restricted diffusion can mimic malignancy

Diffusion-weighted imaging (DWI) is an increasingly utilized sequence in the assessment of abdominal and pelvic lesions. Benign lesions containing hemorrhagic products, with conglomerates of tightly packed blood cells or fibers, can have restricted water diffusion on DWI and apparent diffusion coefficient maps. Such lesions can have restricted diffusion erroneously attributed to malignancy. This review illustrates benign hemorrhagic lesions displaying restricted diffusion, with histopathologic correlation in relevant cases.

Soft-Tissue Sarcomas of the Abdomen and Pelvis: Radiologic-Pathologic Features, Part 2-Uncommon Sarcomas

Soft-tissue sarcomas occurring in the abdomen and pelvis are an uncommon but important group of malignancies. Recent changes to the World Health Organization classification of soft-tissue tumors include the movement of gastrointestinal stromal tumors (GISTs) into the soft-tissue tumor classification. GIST is the most common intraperitoneal sarcoma. Liposarcoma is the most common retroperitoneal sarcoma, and leiomyosarcoma is the second most common. GIST, liposarcoma, and leiomyosarcoma account for the majority of sarcomas encountered in the abdomen and pelvis and are discussed in part 1 of this article. Undifferentiated pleomorphic sarcoma (previously called malignant fibrous histiocytoma), dermatofibrosarcoma protuberans, solitary fibrous tumor, malignant peripheral nerve sheath tumor, rhabdomyosarcoma, extraskeletal chondro-osseous sarcomas, vascular sarcomas, and sarcomas of uncertain differentiation uncommonly arise in the abdomen and pelvis and the abdominal wall. Although these lesions are rare sarcomas and their imaging features overlap, familiarity with the locations where they occur and their imaging features is important so they can be diagnosed accurately. The anatomic location and clinical history are important factors in the differential diagnosis of these lesions because metastasis, more-common sarcomas, borderline fibroblastic proliferations (such as desmoid tumors), and endometriosis have imaging findings that overlap with those of these uncommon sarcomas. In this article, the clinical, pathologic, and imaging findings of uncommon soft-tissue sarcomas of the abdomen and pelvis and the abdominal wall are reviewed, with an emphasis on their differential diagnosis.

Shining light in a dark landscape: MRI evaluation of unusual localization of endometriosis

Endometriosis is a disease distinguished by the presence of endometrial tissue outside the uterine cavity with intralesional recurrent bleeding and resulting fibrosis. The most common locations for endometriosis are the ovaries, pelvic peritoneum, uterosacral ligaments, and torus uterinus. Typical symptoms are secondary dysmenorrhea and cyclic or chronic pelvic pain. Unusual sites of endometriosis may be associated with specific symptoms depending on the localization. Atypical pelvic endometriosis localizations can occur in the cervix, vagina, round ligaments, ureter, and nerves. Moreover, rare extrapelvic endometriosis implants can be localized in the upper abdomen, subphrenic fold, or in the abdominal wall. Magnetic resonance imaging (MRI) represents a problem-solving tool among other imaging modalities. MRI is an advantageous technique, because of its multiplanarity, high contrast resolution, and lack of ionizing radiation. Our purpose is to remind the radiologists the possibility of atypical pelvic and extrapelvic endometriosis localizations and to illustrate the specific MRI findings. Endometriotic tissue with hemorrhagic content can be distinguished from adherences and fibrosis on MRI imaging. Radiologists should keep in mind these atypical localizations in patients with suspected endometriosis, in order to achieve the diagnosis and to help the clinicians in planning a correct and complete treatment strategy.

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.

Rectus Abdominis Endometrioma after Caesarean Section

Isolated rectus abdominis muscle endometriosis is very uncommon with less than 20 case reports being published to date since its first description in 1984 by Amato and Levitt. We report another case of isolated rectus abdominis endometriosis in a 37-year-old patient with a previous caesarian section. We also discuss the diagnostic and treatment particularities in these patients. In our case, the treatment was only surgical and currently the patient is disease-free during the 24-month follow-up.

Abdominal Wall Endometriosis on the Right Port Site After Laparoscopy: Case Report and Literature Review

BACKGROUND

Endometriosis can be intrapelvic or, rarely, extrapelvic. Endometriosis involving the rectus abdominis muscle on the trocar port site is a rare event; until now, only 16 cases have been reported in the literature. The majority of cases were associated with previous abdominal surgery such as diagnostic laparoscopy, cyst excision, appendectomy, myomectomy, or cholecystectomy. We review all the reported cases of this unusual form of extrapelvic endometriosis.

CASE REPORT

We report a new case of abdominal wall endometriosis at the trocar port site in the rectus abdominis muscle in a woman who had undergone 2 laparoscopies for endometriosis in the 3 years before coming to our attention. The diagnosis was made by sonography. We performed a surgical resection of the lesion with a free macroscopic margin of 5-10 mm.

CONCLUSION

Endometriosis should be considered in the differential diagnosis of any abdominal swelling. In our experience, surgery is the treatment of choice.

Intramuscular abdominal wall endometriosis treated by ultrasound-guided ethanol injection

Abdominal wall endometriosis (AWE) is a rare condition that usually develops in a surgical scar resulting from a Caesarean section. While commonly seen in the cutaneous and subcutaneous fat tissue at the Caesarean scar level, its intramuscular localization is quite rare. Its treatment options consist of the excision of the lesion and/or hormonal therapies, although wide surgical excision is the treatment of choice in the literature. Wide surgical excision may create a defect in the abdominal wall and may increase the risk of hernia formation and mesh complications. This case report describes the clinical and radiological findings and treatment modalities of endometriosis that have appeared in the rectus abdominis muscle of a 25-year-old patient at the Caesarean scar level. Sclerotherapy may be used for endometrioma. We present a new and alternative treatment method using ultrasound-guided intralesional ethanol injection for AWE. Compared with the complications of surgical excision, the complications of sclerotherapy by ethanol are at a more acceptable level. Sclerotherapy by ethanol injection may be an alternative treatment to surgery for AWE.

Abdominal wall endometriosis: 12 years of experience at a large academic institution

OBJECTIVE

The objective of the study was to review patient characteristics and intraoperative findings for excised cases of abdominal wall endometriosis (AWE).

STUDY DESIGN

A 12 year medical record search was performed for cases of excised AWE, and the diagnosis was confirmed on pathological specimen. Descriptive data were collected and analyzed.

RESULTS

Of 65 patients included, the primary clinical presentation was abdominal pain and/or a mass/lump (73.8% and 63.1%, respectively). Most patients had a history of cesarean section (81.5%) but 6 patients (9.2%) had no prior surgery. Time from the initial surgery to presentation ranged from 1 to 32 years (median, 7.0 years), and time from the most recent relevant surgery ranged from 1 to 32 years (median, 4.0 years). Five patients (7.7%) required mesh for fascial closure following the resection of the AWE. We were unable to demonstrate a correlation between the increasing numbers of open abdominal surgeries and the time to presentation or depth of involvement. Age, body mass index, and parity also were not predictive of depth of involvement. There were increased rates of umbilical lesions (75% vs 5.6%, P < .001) in nulliparous compared with multiparous women as well as in women without a history of cesarean section (66.7% vs 1.9%, P < .001).

CONCLUSION

In women with a mass or pain at a prior incision, the differential diagnosis should include AWE. Although we were unable to demonstrate specific characteristics predictive for AWE, a large portion of our population had a prior cesarean section, suggesting a correlation.

The importance and perspective of magnetic resonance imaging in the evaluation of endometriosis

MR imaging is becoming increasingly important in the assessment of patients with endometriosis. Its multiplanar capabilities and superior soft tissue contrast are particularly useful in the detection of deep infiltrating endometriotic implants. Endometriosis, defined as the presence of endometrial glands and stroma outside the endometrium, is among the most common gynaecological disorders affecting women in their reproductive age. The diagnosis and evaluation of the extension of endometriosis are difficult only with physical examination and laparoscopy. According to the authors' personal experience, a special MRI technique and some imaging guidelines regarding different anatomical localizations of endometriosis are discussed. This review is a brief presentation of current evidence on the diagnostic accuracy of MRI in the evaluation of endometriosis concerning other diagnostic methods, the limitations of MRI and its essential usefulness for preoperative diagnosis of deep pelvic endometriosis, and future perspectives in monitoring this disease.

Abdominal wall endometrioma: ultrasonographic features and correlation with clinical findings

BACKGROUND

The diagnosis of abdominal wall endometrioma (AWE) is often confused with other surgical conditions. Certain factors relating to knowledge of the clinical history of the disease make correct diagnosis and treatment difficult.

AIMS

To present the clinical findings and ultrasonographic (US) features of AWE with special emphasis on size-related features.

STUDY DESIGN

This study reviewed abdominal wall endometriomas during a 2-year period in the Radiology Department of Sifa University Hospital, Izmir.

METHODS

Eleven women (mean age 32.6 years) with 12 scar endometriomas (mean diameter 29.2 mm) were consecutively evaluated by US and Colour Doppler examination (CDUS) prior to surgery. Lesions were grouped into large (≥3 cm) and small nodules. Vascularisation was classified as location (central, peripheral and mixed) and severity (absent, moderately vascular and hypervascular). In each patient, the nature of pain (absent, cyclic: associated with menstruation and continuous), historical and clinical data were documented. Four patients underwent Magnetic Resonance Imaging and their findings were presented. Fisher's exact test, χ(2) test for categorical data and the unpaired T-test for continuous variables were used for statistical analysis.

RESULTS

In all the women, US of the AWE showed the presence of a solid hypoechoic mass (less echogenic than the surrounding hyperechoic fat) within the abdominal wall. There was a significant correlation between AWE sizes with repeated caesareans and the mean time between the last operation and admission to hospital (p<0.05). Large endometriomas showed increased central vascularity (p<0.05). Cyclic pain was more frequent in small lesions, whereas continuous pain was more commonly found in patients with larger lesions (p<0.05).

CONCLUSION

AWE is often misdiagnosed clinically because endometriosis may occur years after the caesarean section, the pain is often non-cyclic in nature, and there is not always a palpable tender mass. The sonographic and Doppler findings, along with proper correlation with clinical data, may substantially contribute to the correct diagnosis of endometrioma.

Chronic Umbilical Discharge: An unusual presentation of endometriosis

Umbilical endometriosis is an important differential diagnosis of any umbilical lesion. A 35-year-old type 2 diabetic woman presented with intermittent umbilical discharge which failed to respond to various antibiotics. An ultrasound scan and MRI scan failed to show any obvious abnormality. The umbilicus was excised and histology confirmed endometriosis. Surgical excision provides a definitive diagnosis and curative treatment for isolated endometriosis.

The abdominal wall lumps and bumps: cross-sectional imaging spectrum

This article focuses on the cross-sectional imaging spectrum of abnormalities that affect the abdominal wall, with emphasis on magnetic resonance imaging (MRI). Cross-sectional imaging is valuable for diagnosing and evaluating the extent of abdominal-wall masses. With the increasing use of MRI, it is often possible to reach a diagnosis or narrow the differential diagnosis, thereby guiding effective management. Neoplastic and non-neoplastic pathologies will be illustrated, and the distinctive imaging characteristics of these entities will be highlighted.

Laparoscopic trocar port site endometriosis: a case report and brief literature review

Endometriosis is defined as the presence of ectopic endometrial tissue outside the lining of the uterine cavity. It occurs most commonly in pelvic sites such as ovaries, cul-de-sac, and fallopian tubes but also can be found associated with the lungs, bowel, ureter, brain, and abdominal wall. Abdominal wall endometriosis, also known as scar endometriosis, is extremely rare and mainly occurs at surgical scar sites. Although many cases of scar endometriosis have been reported after a cesarean section, some cases of scar endometriosis have been reported after an episiotomy, hysterectomy, appendectomy, and laparoscopic trocar port tracts. To our knowledge, 14 case reports related to trocar site endometriosis have been published in the English language literature to date. Herein, we present the case of a 20-year-old woman (who had been previously operated on for left ovarian endometrioma 1.5 years ago by laparoscopy) with the complaint of a painful mass at the periumbilical trocar site with cyclic pattern. Consequently, although rare, if a painful mass in the surgical scar, such as the trocar site, is found in women of reproductive age with a history of pelvic or obstetric surgery, the physician should consider endometriosis.

Subcutaneous abdominal wall masses: radiological reasoning

OBJECTIVE

A 36-year-old woman presented to her primary care physician with right lower abdominal pain. Her physician subsequently requested a CT to rule out appendicitis. Contrast-enhanced CT was performed and revealed no evidence of appendicitis but showed two subcutaneous ovoid soft-tissue masses anterior to the rectus sheath in the upper pelvis. Pelvic MRI confirmed the two masses, which showed mild enhancement. The objective of this article is to discuss a diagnostic approach to subcutaneous soft-tissue masses in the abdominal wall. Diagnosis was endometriosis of the abdominal wall.

CONCLUSION

Integrating salient imaging findings with clinical history is crucial when approaching the diagnosis of subcutaneous soft-tissue masses. The diagnosis of endometriosis should be entertained when soft-tissue masses are seen in the distribution of a cesarean section scar in a woman of reproductive age. Pain, particularly with a cyclic pattern, is highly suggestive of endometriosis. If endometriosis is suspected on CT or ultrasound, MRI can be performed for further evaluation. Definitive diagnosis is made with biopsy. Because subcutaneous nodules are so amenable percutaneous biopsy, imaging features, although of interest, are somewhat ancillary to the diagnostic workup.

Nuck canal endometriosis: MR imaging findings and clinical features

OBJECTIVE

The purpose of this study was to describe the MR imaging findings of Nuck canal endometriosis (NCE).

MATERIALS AND METHODS

In a 10-year period, 486 out of 612 patients, with laparoscopically and/or surgically proven diagnosis of pelvic endometriosis, underwent MR imaging examination. The examinations were reviewed by two urogenital experienced radiologists working in consensus. Data analysis included: lesions location, size, morphological and signal intensity pattern, involvement of the adjacent muscles, and tendons.

RESULTS

In 372 out of 486 patients an MRI diagnosis of endometriosis was made. NCE was found in eight patients. All the lesions were located on the right side. The mean size of the lesions was 2.5 cm (range 1.5-4.5 cm). Two patterns of NCE were found: type 1, prevalently cystic (n = 2); and type 2, prevalently solid with small scattered cysts within lesion (n = 6). In all the patients, hemorrhagic hyperintense cysts could be seen on T1-weighted images. In four patients, the lesions involved the inguinal canal, and in another four patients, the lesions were only outside the inguinal canal. Involvement of the abdominis rectus muscle was seen in two patients, and of the adductor common tendon in two patients.

CONCLUSION

MR imaging permits the diagnosis of NCE as well as the evaluation of exact extension of the disease.