Endometriosis, affecting 6%-10% of women of reproductive age, can lead to severe symptoms such as chronic pelvic pain and infertility. Among its rarer manifestations is abdominal wall endometriosis (AWE), which has been increasingly reported following cesarean deliveries. This case discusses a 39-year-old woman who presented with a 13-year history of cyclical pain at her cesarean section scar, exacerbated over the last year by the development of a painful abdominal mass. Medical evaluations indicated endometriosis at the scar, with further investigations including ultrasound and magnetic resonance imaging showing involvement of the rectus abdominis muscle. Elevated tumor markers HE4 and CA-125, along with a biopsy, confirmed adenocarcinoma. The patient underwent extensive surgical treatment, including the resection of the mass, hysterectomy, bilateral salpingo-oophorectomy, and lymphadenectomy. Pathology confirmed moderately differentiated infiltrative adenocarcinoma originating from endometriosis. Despite the absence of postoperative chemotherapy, the patient showed no recurrence, emphasizing the effectiveness of comprehensive surgical management. This case highlights the critical importance of recognizing the potential for malignant transformation in AWE, particularly following cesarean deliveries, and underscores the necessity for vigilant monitoring and personalized treatment strategies. The management of AWE, especially when malignant transformation is suspected, necessitates a multidisciplinary approach similar to that used in ovarian cancer, focusing on rigorous surgical intervention and the potential for adjuvant therapies.

Background: Malignant-associated abdominal wall endometriosis (AWE) is a rare pathology, likely to occur in 1% of scar endometriosis. The objectives of this study were to update the evidence on tumor degeneration arising from AWE to notify about the clinical characteristics, the different treatments offered to patients and their outcomes. Methods: A comprehensive systematic review of the literature was conducted. PubMed, Embase and Cochrane Library databases were used. Prospero (ID number: CRD42024505274). Results: Out of the 152 studies identified, 63 were included, which involved 73 patients. The main signs and symptoms were a palpable abdominal mass (85.2%) and cyclic pelvic pain (60.6%). The size of the mass varied between 3 and 25 cm. Mean time interval from the first operation to onset of malignant transformation was 20 years. Most common cancerous histological types were clear cell and endometrioid subtypes. Most widely accepted treatment is the surgical resection of local lesions with wide margins combined with adjuvant chemotherapy. The prognosis for endometriosis-associated malignancy in abdominal wall scars is poor, with a five-year survival rate of around 40%. High rates of relapse have been reported. Conclusions: Endometrial implants in the abdominal wall should be considered as preventable complications of gynecological surgeries. Special attention should be paid to women with a history of cesarean section or uterine surgery.

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.

UNASSIGNED: Endometriosis is one of the most frequent gynecologic disorders, clinically confirmed or suspected in one of nine women by the age of 44 years. Its location of occurrence can be classified into intra and extra pelvic. Abdominal wall endometriosis (AWE) is one of its rare location, with frequency of 0.04 to 5.5 %. Furthermore there are only a few cases of AWE in Indonesia that have been reported.
METHODS: Here we present two Indonesian patients at a General Hospital in Tangerang, Indonesia. The first patient, 26 years old, complained of an umbilical mass 2 years after caesarean section. The second patient, 36 years old, complained of an umbilical mass since 8 months, with no history of prior surgery. Both patients had pre-operative ultrasonography (US) and underwent wide local excision. Histopathology examination with presence of endometrial glandular components and endometrial-like stroma confirmed the diagnosis of AWE.
UNASSIGNED: AWE is defined as any endometrial tissue found superficial to the peritoneum, locating most commonly at umbilical, inguinal area, and anterior abdominal wall. Pre-operative diagnostic tools include abdominal ultrasonography (US) or abdominopelvic computed tomography (CT) scan. Since treatment with medications is usually not effective, surgical treatment is recommended, along with confirmation by histopathological examination.
CONCLUSIONS: Diagnosis of AWE should be suspected in all women with symptoms of an abdominal mass and cyclic pain, especially if the patient had history of surgery at the abdominal region. AWE is quite rare, but its symptoms can affect quality of life. Hence, a multi-disciplinary approach is necessary, with the strongly recommended treatment of wide local excision to prevent recurrence and malignant transformation.

UNASSIGNED: Endometriosis developing in a cesarean section (CS) scar is an unusual event. Malignant transformation arising on the background of scar endometriosis in the abdominal wall is extremely rare. Herein we report a case of clear cell carcinoma (CCC) arising in the abdominal wall from endometriosis tissues following CS and review previous literature.
UNASSIGNED: A 48-year-old gravida 2 para 1 female presented with an abdominal wall mass at her CS scar, which increased in size and became painful in the last 2 years. Physical examination showed a multilocular solid mass of about 13 cm, at the previous CS scar. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a 12.8cm × 7.7cm multi-septate cystic lesion on the anterior abdominal wall, and histological examination showed that CCC was caused by the transformation of abdominal wall endometriosis (AWE).
UNASSIGNED: An endometriosis-associated malignancy should be considered in the differential with any enlarging mass in the abdominal wall scar.

Malignant transformation of abdominal wall endometriosis (AWE) is rare. The clinical characteristics and treatment of malignant transformation of AWE are not well known. Therefore, in this review, we performed a thorough search for malignant transformation of AWE on MEDLINE and Web of Science from their inception to May 2021. In total, the data of 46 patients with malignant transformation of AWE were retrieved, and all the data on these patients were collected. After reviewing and analyzing the clinical parameters, we found that cesarean scar was the most common site of malignant transformation of AWE, and the most common pathological type of malignant transformation of AWE was clear cell cancer, followed by endometrioid adenocarcinoma. The main symptoms of malignant transformation of AWE included an abdominal nodule or mass, and ultrasonography was the first choice for diagnosis. The most widely accepted treatment was surgical resection of local lesions with adjunctive chemotherapy and/or radiotherapy, and the overall survival of patients with malignant transformation of AWE was poor. In conclusion, malignant transformation of AWE is rare, and the prognosis is poor. Thus, improving abdominal surgical technology and avoiding iatrogenic ectopia and implantation of the endometrium are necessary to prevent malignant transformation of AWE.

Endometriosis is a debilitating disease characterized by endometrial glands and stroma outside the endometrial cavity. Abdominal wall endometriosis (AWE) indicates the presence of ectopic endometrium between the peritoneum and the skin, including subcutaneous adipose tissue and muscle layers, often following obstetric and gynecological surgical procedures. AWE is a not infrequent gynecological surgical complication, due to the increasing number of cesarean sections worldwide. In this pictorial review, we discuss the importance of medical history and physical examination, including the main ultrasound features in the diagnosis of AWE.

OBJECTIVE: The scar of cesarean section (CS) is the most common site of abdominal wall endometriosis (AWE), whose tumor degeneration has been reported in an increasing number of cases; the most frequent histological type is clear cell carcinoma (CCC).
METHODS: We conducted a systematic research of the literature, collecting data regarding the evidence on tumor degeneration from AWE after CS. Moreover, we reported a case of clear cell borderline tumor (CCBT) originating from AWE.
RESULTS: We included data of 37 patients with diagnosis of CCC. The average time between the last CS and the diagnosis of CCC was around 15 years. Overall, 26.0% and 73.9% patients received exclusive local abdominal resection of the lesion and additional surgery, respectively. Lymph nodes involvement was detected in 26.0 % patients and adjuvant chemotherapy was administered in 52.0 % cases. During follow-up period, 15.2% patients died of disease, 32.6% had no evidence of disease, and 17.4% recurred. We diagnosed a CCBT arose in a patients with AWE and a personal history of several surgical procedures for endometriosis, a CS and a subsequent transverse laparotomy. We performed an open bilateral ovariectomy and a large excision of the endometriotic abdominal lesion.
CONCLUSIONS: Tumor degeneration from AWE seems to be a real occurrence with an increasing number of events. Considering the lack of risk factors and diagnostic instruments for tumor degeneration, the removal of AWE localization could be advisable, even though there was long average time between the trigger surgery and the tumor finding.

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.
RESULTS: 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.
CONCLUSIONS: 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.

OBJECTIVE: Clear cell carcinoma of the abdominal wall is a sporadic event. To date, about thirty cases have been reported in the literature. This article provides a case report and literature review of an infrequent occurrence with poor prognosis.
METHODS: A 45-year-old woman with pelvic pain and an abdominal mass came to our attention. Her medical history was notable for two previous cesarean sections. Physical examination revealed a smooth, multilocular mass measuring about 20 cm, arising from the previous surgical scar. Histology revealed clear-cell carcinoma resulting from the transformation of abdominal wall endometriosis. Given the disease extent, the patient underwent front-line chemotherapy. After several and multiple chemotherapy regimens, there was a disease progression that resulted in the death of the patient in 7 months. The literature review showed that a previous cesarean section was present in 91% of cases. Besides, approximately 26.5% of women died within 12 months of being diagnosed. The mean age of women was 45.88 years, while the average size of the lesion was 11 cm.
CONCLUSIONS: Clear cell carcinoma is a rare but occurring event. Middle-aged women showing an abdominal wall mass in close relation with a surgical scar from a previous cesarean section must be promptly investigated. Treatment options usually include surgery and chemotherapy with poor results.