Delayed Presentation of Cutaneous Endometriosis at the Cesarean Section Scar: A Case Report

Endometriosis is defined as the ectopic presence of functional endometrial glands and stroma in any organ other than the uterus.[] It usually occurs in pelvic organs, such as the ovaries, bowel, or pelvic peritoneum; however, it can occur beyond the area where the pelvic organs are located. Cutaneous endometriosis, which is also known as abdominal wall endometriosis, is a rare site of endometriosis.[] It can implant on abdominal wall scars following any open gynecological surgery. Iatrogenic causes of endometriosis in the skin are classified as secondary cutaneous endometriosis.[] The overall incidence of secondary cutaneous endometriosis in women who undergo gynecological surgical procedures is about 3.5%, while the reported incidence of secondary cutaneous endometriosis in females who underwent a cesarean section is limited to 0.8%.[] The average reported latency period between the cesarean section surgery and the development of secondary endometriosis is 31 months.[] We present a case of secondary cutaneous endometriosis at the site of a cesarean section scar that appeared 4 years following the surgery. CASE REPORT A 45-year-old female was referred to the dermatology clinic at King Saud University Medical City complaining of a large abdominal mass over the left lower abdomen. The patient had undergone four cesarean section surgeries. The last surgery was 4 years before starting to develop this lesion. It had been gradually increasing in size over the past 7 years and was associated with fluctuating pain. With further history taking the pain was found to be preceding her menstrual cycles. The lesion was also associated with on-and-off itching and a foul smell. She had never complained of bleeding or ulceration from this mass. Her past medical history revealed severe iron deficiency anemia. Her hemoglobin level was 89 g/L (normal: 121–151 g/L) and her ferritin level was 3.7 ng/mL (normal: 12–150 ng/mL). However, she was never diagnosed with any gynecological disease. A physical examination revealed a well-defined multinodular exophytic mass measuring 5 cm × 4 cm, with a deeper component felt on palpation located over the left side of the cesarean section scar [Figure 1]. Her vital signs were normal, there were no palpable inguinal or axillary lymph nodes, and no hepatosplenomegaly was found. Initially, multiple noninvasive investigations were performed. An enhanced computed tomography (CT) scan of the abdomen and pelvis showed a cutaneous and subcutaneous enhancing soft-tissue lesion with an irregular wall measuring 5 cm × 4.4 cm × 6 cm in transverse, anteroposterior, and craniocaudal dimensions, respectively. There was no intra-abdominal extension or suspicious enlarged regional lymph nodes. The uterine cervix was bulky and heterogeneous, filling up the proximal vaginal cavity. The uterus was bulky with a nonspecific anterior wall calcific focus; however, no obvious lesions were observed. The CT scan was followed by magnetic resonance imaging (MRI), which illustrated an ill-defined enhancing mass lesion from the skin with an extension into the deep subcutaneous fat. This extension showed some stranding extending to the adjacent lower rectus abdominis muscle on the left side. The MRI also showed a small enhancing deep inguinal lymph node, along with some inflammatory changes and stranding extending from the lesion superiorly and laterally [Figure 2]. In addition, an incisional biopsy of a grey-tan soft tissue collectively measuring 2.0 cm × 1.2 cm × 0.9 cm was obtained. The gross section revealed an irregular smooth outer surface and a pale-yellow homogeneous cut surface. A histopathological examination of the tissue using hematoxylin and eosin stain demonstrated multiple dilated glandular structures of variable dimensions lined by endometrial-type epithelium and surrounded by an endometrial-type stroma. These findings confirmed the diagnosis of endometriosis [Figure 3]. The patient was referred to the obstetrics and gynecology department for further management.

Endometriosis is a common gynecological disease. The percentage of affected females of childbearing age varies between 15% and 40%. However, cutaneous endometriosis is very rare, being only reported in approximately 0.5%–1% of all patients with endometriosis.[] The risk factors for cutaneous endometriosis include low body mass index, nulliparity, early menarche, late menopause, and the presence of endometriosis in a first-degree relative.[] Our presented case had her menarche at the age of 13. However, she was para four with a normal body mass index and had no family history of endometriosis. A recent review showed that 34 out of 35 patients with abdominal wall endometriosis had a history of cesarean section surgery.[] Our case presented extra-pelvic endometriosis arising over the left side of the cesarean section scar which is the most common location of cutaneous endometriosis reported in the literature.[] The pathogenesis of cutaneous endometriosis is not yet well understood. Multiple theories have been discussed in the literature; however, direct mechanical implantation seems to be the most representative theory to explain scar endometriosis.[] The diagnosis of cutaneous endometriosis can be reached following a thorough patient history and physical examination. Ultrasonography, Doppler sonography, CT scan, and MRI can be used as noninvasive tools to determine the type of the lesion. However, the most accurate diagnostic method is a histopathological examination. The histopathological findings should include the endometrial glands and stroma.[] In our case, CT scan and MRI were used initially. However, the specificity values of both examinations are low. Therefore, the diagnosis was confirmed by a histopathological examination. Although it is extremely rare, the malignant transformation of abdominal wall endometriosis has been reported.[] Clear cell carcinoma and adenocarcinomas were the most reported malignancies.[,] Kim et al. recommended surgical excision with clear margins of at least 1 cm.[] Adjuvant medical treatment can be used before and after the surgical excision, including hormonal therapy such as combined oral contraceptives, progestins, and danazol.[,,] Some cesarean section practices, including certain bleeding control methods, abdominal cavity washing before closure, and minimizing subcutaneous dead space were recommended in previous studies to minimize the risk of cutaneous endometriosis.[,] In conclusion, cutaneous endometriosis is a rare skin disease that can appear a long time following a gynecological or an obstetrical procedure, with nonspecific symptoms. Dermatologists should consider cutaneous endometriosis when a mass or nodule is arising over a surgical scar of a gynecological surgery, especially if it is associated with cyclic pain or bleeding. A histopathological analysis is essential to confirm the diagnosis. Although there are no clear guidelines for management, complete excision of the lesion is recommended. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

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