Scar endometriosis is a rare type of extrapelvic endometriosis that is associated with obstetrical and gynecological surgeries. Scar endometriosis is reported in only 0.03-0.15% of all cases of endometriosis. We are reporting a case of 39-year-old female patient presenting with scar endometriosis 10 years after her last lower segment cesarean section (LSCS). The patient came to the Gynecology OPD, NIUM Hospital on 6th May 2019 with the complaint of suprapubic swelling since 6 months, which was growing slowly. Her menstrual history was regular, but she had lower abdominal pain during menstruation. Patient had 2 children delivered by LSCS. On clinical history, examination, USG and FNAC finding, the swelling was diagnosed as scar endometriosis.

Keywords: Endometriosis, abdominal scar, LSCS and prevention

Endometriosis refers to the presence of endometrial glands and stroma outside the uterus. It is estimated to affect 10-15% of all women of reproductive age, i.e., 18-45 years, and 70% of women who have chronic pelvic pain. Endometriosis occurs in abdominal, extra-abdominal and remote areas. Scar endometriosis is reported in only 0.03-0.15% of all cases of endometriosis. Several factors have been consistently associated with risk for endometriosis, such as early age at menarche, late menopause, frequent menstrual cycles, low parity, use of estrogen pills, estrogen producing tumors, obesity. The cause of endometriosis is unclear, but several theories have been reported. One possible mechanism is retrograde menstruation. This retrograde flow, along with potential hematogenous or lymphatic circulation, may result in the seeding of endometrial tissue in ectopic sites. Another theory is direct implantation of endometrial tissue during surgical procedures like lower segment cesarean section (LSCS), hysterectomy, myomectomy, episiotomy, etc. Other factors, such as genetic, environmental, hormonal, inflammatory or immunological, may also result in implantation of endometrial tissues on ectopic sites.

Clinical presentation of endometriosis varies in different women. Patients often present with symptoms such as intermenstrual bleeding, dysmenorrhea, dyspareunia, dyschezia and dysuria. Pelvic pain may present before onset of menstruation. Often, endometriosis can be asymptomatic, only diagnosed during evaluation for infertility. The lesions can be peritoneal lesions, superficial implants or cysts on the ovary, or deep infiltrating disease. Classification of endometriosis associated symptoms has been established by the American Society for Reproductive Medicine (ASRM) based on the morphology of peritoneal and pelvic implants such as red or pink, white and black lesions, percentage of involvement of organ. Endometriosis in bowel, urinary tract, fallopian tube, vagina, cervix, skin or other locations are identified as per ASRM guidelines. Stages of endometriosis according to ASRM guidelines are stage I, II, III and IV. These are based on the point scores and correspond to minimal, mild, moderate and severe endometriosis. Early diagnosis and intervention could ultimately improve the quality of life and preserve fertility.

The goal of this paper is to highlight an atypical case of scar endometriosis.

A 39-year-old female patient came to Gynecology OPD of National Institute of Unani Medicine (NIUM), Hospital on 6th May 2019 with the complaint of suprapubic swelling, which was gradually increasing in size since last 6 months. She also complained that the pain in lump is worse during menstruation. Her age of menarche was 15 years. She was having regular menstruation with normal flow, but history of dysmenorrhea was present. She had no history of any other systemic illness. Her married life was 18 years. She had 2 children, both were delivered by LSCS, and history of 1 spontaneous abortion was also present. The patient was tubectomized after cesarean section. Her last child birth was 10 years back. According to her history before surgery, she was fit and well with no documented history of endometriosis. Vitals were normal and her body mass index (BMI) was 26.2 kg/m2.

On examination, a suprapubic swelling of approxi­mately 8 × 5 cm was found at the site of lower part of cesarean scar. On palpation, local temperature was raised, mass was irregular extending to pelvic region (Fig. 1). On vaginal examination, uterus was found anteverted, bulky, mobile and fornices free. On initial examination, it was diagnosed as a lump. Consultant gynecologist advised for ultrasonography (USG) and cytology of lump. USG was done on 14/5/2019; findings showed large well-defined hypoechoic solid lesion approximately 8.6 × 6.5 × 7.1 cm noted in subcutaneous plane in midline of lower anterior abdominal wall and suprapubic region, suggestive of endometriosis. For confirmation, fine needle aspiration cytology (FNAC) was done on the same day, i.e., 14/5/2019, which reported benign cellular stromal fragments of endometrium with occasional benign glands. No granuloma or malignancy was found. These findings suggested endometriosis. Extra-abdominal endometriosis occurs at the time of surgical procedures like myomectomy, hysterectomy or LSCS, etc. Here in this case, previous history of 2 LSCS was present, which suggested the swelling may be due to direct implantation of endometrial tissue during cesarean section. This endometrial tissue grows every month in response to hormones especially estrogen. Estrogen helps in proliferation of endometrial tissue every month, hence, the suprapubic swelling was increasing slowly.

Scar endometriosis is a rare entity that usually follows previous abdominal surgery, especially early hysterectomy and cesarean section. There are numerous sites where extrapelvic endometriosis has been reported. These include lungs, pleura, bladder, kidney, bowel, omentum, umbilicus and abdominal wall. Endometriosis involving the abdominal wall is a rare occurrence; however, it should be considered in the differential diagnosis of abdominal wall masses in females. The typical clinical scenario involves a parous female with a history of gynecological or obstetric surgery presenting with a painful nodule or lump. The severity of pain and size of the lump may vary with menstrual cycle. In this case, the patient remained without a diagnosis for 10 years. Gynecological history and physical examination is important in finalizing the diagnosis. The history revealed that the pain coincided with her menstrual cycle. The clinical examination revealed a soft, nonreducible swelling located in pubic region. It was tender on palpation. On initial examination, it was diagnosed as a lump. Based on the gynecological history of a cyclical increase in the size and severity of pain, an endometrioma was also included in the differential diagnosis.

Surgical scar endometriosis is believed to result from deposits of endometrial cells during surgical intervention. These cells are then stimulated by estrogen to produce endometriomas. Although relatively uncommon, it was well-documented in clinical practice that scar endometriosis occurs with different types of incisions where contact has possibly occurred with endometrial tissue. The endometriomas may develop 1-20 years postoperatively; examples include cesarean section, laparoscopy, tubal ligation and hysterectomy. Of these, cesarean section and hysterectomy are the most common. The incidence after cesarean section is difficult to determine, but estimates range from 0.03% to 0.47%. Minaghlia et al analyzed 30 years of incisional endometriosis after cesarean section and reported the incidence of scar endometriosis to be 0.08%. Frequency of scar endometriosis increases by number of cesarean section and laparoscopy performed in recent years. Other authors have reported an incidence of 0.2% in all cesarean sections performed. To make a definitive preoperative diagnosis of endometriosis is difficult.

Positive histology confirms the diagnosis of endo­metriosis; however, negative histology does not rule it out. Additionally, it is controversial if histology should be obtained if there is only peritoneal disease. Visual inspection usually suffices, but histological confirmation of at least one lesion is ideal. In comparison with laparoscopy, transvaginal ultrasound seems to have no value in diagnosis of peritoneal endometriosis. However, it is a potential tool to make and exclude the diagnosis of ovarian endometrioma. Transvaginal sonography (TVS) may have a role in the diagnosis of disease involving the bladder or rectum. Medical imaging plays a role in locating the mass and ruling out hernia and other conditions, for example lipoma, abscess and suture granuloma. Magnetic resonance imaging (MRI) remains the most useful imaging modality to exclude other pathology. In this case, the scar endometriosis was diagnosed by USG and was confirmed by FNAC of the lump.

Endometriosis is a debilitating disease that impacts the quality of life of adolescent and adult patients. Delayed diagnosis is common and may lead to a decline in reproductive potential and fertility. A semi- or non-invasive diagnostic biomarker would be a useful tool to identify patients early in the disease process, thus improving outcomes, including less pain and better fertility. The occurrence of abdominal wall scar endometriosis after cesarean section has been a definite entity; steps to prevent this complication have not been explained. Literature recommends that cleaning, irrigation with saline and closure of abdominal wound will prevent scar endometriosis.