Cesarean scar endometriosis

Endometriosis is defined as the presence of functional endometrial glands and stroma outside the uterine cavity. It is one of the common gynecological disorders in women of reproductive age group. Its prevalence in the general population varies between 0.7% and 44%.[] The common sites of the occurrence of endometriosis in the pelvis are ovaries, uterosacral ligaments, round ligaments, uterine ligaments, pelvic peritoneum, and rectovaginal septum. Extrapelvic endometriosis is rare and found in the nervous system, thorax, urinary tract, gastrointestinal tract, and most frequently in abdominal wall.[] It presents in women who have undergone a previous abdominal or pelvic surgeries.[] The incidence of scar endometriosis is 0.03%–0.15% of all cases of endometriosis.[] The most accepted theory for the cause of scar endometriosis is the iatrogenic transplantation of endometrial implants to wound during abdominal and pelvic surgery.[] The present study discusses a case of scar endometriosis and reviews the literature to elucidate physical signs and symptoms that may lead to earlier diagnosis and prompt treatment. CASE REPORT A 30-year-old female came to gynecology outpatient with complaints of swelling and pain on the right side of the previous cesarean scar for 6 months. She is P1 L1, with one previous lower segment cesarean section done 3½ years ago, for fetal distress. Her postoperative period was uneventful. She has regained her menses after 4 months of lower segment cesarean section. She described pain and swelling above the cesarean scar for 6 months, which was gradually increasing during menstruation. There was no other significant medical history. General examination was within normal limits. Per abdominal examination revealed a healed cesarean scar with firm nodular mass of size 4 cm × 4 cm, at the right side of the Pfannenstiel cesarean scar. Mass was nontender with restricted mobility. Her USG examination showed two well-defined hypoechoic solid lesion 30 mm × 30 mm and 40 mm × 40 mm in subcutaneous plane and muscular planes, respectively. Differential diagnosis of desmoid tumor, stitch granuloma, lymphadenopathy, and scar endometriosis was made [Figure 1]. The patient was subjected to fine-needle aspiration cytology (FNAC) which was suggestive of scar endometriosis. In view of above findings, the patient was posted for wide excision of the abdominal lump. Intraoperatively, there were two lumps, one in subcutaneous plane above rectus sheath of size 2 cm × 2 cm and other in rectus muscle of size 3 cm × 3 cm lumps were excised [Figure 2] and sent for HPE. HPE of both excised masses showed endometrial glands and stroma, confirming the diagnosis of scar endometriosis [Figure 3].

Scar endometriosis usually follows previous abdominal surgery, especially early hysterotomy and cesarean section. Minaglia et al. who analyzed 30 years of incisional endometriosis after cesarean section found the incidence of scar endometriosis to be 0.08%.[] Frequency of scar endometriosis increases by induced number of cesarean section and laparoscopy performed in recent years.[] Direct mechanical implantation seems to be the most plausible theory for explaining scar endometriosis. During the cesarean section, endometrial tissue might be seeded into the wound, and under the same hormonal influences, these cells proliferate.[] The endometrial tissue may have certain abilities that make implantation and transplantation during pregnancy. DeOliveira et al. demonstrate that heavy menstrual blood flow and alcohol consumption were positively related to scar endometriosis, and conversely, high parity may be a protecting factor.[] However, the direct implantation of endometrial tissue cannot explain all cases. The clinical diagnosis of scar endometriosis can be made by a careful history and physical examination. The patients present with a mass near the previous surgical scars, accompanied by increasing colicky-like pain during the menstruation.[] Usually, there is a history of a gynecologic or rarely a nongynecologic abdominal operation. The diagnosis of endometriosis is not suggested until after histology has been performed. Correct preoperative diagnosis is achieved in 20% to 50% of these patients.[] The various methods of investigation, such as ultrasonographic examination, computed tomography, magnetic resonance imaging, Doppler sonography, or fine-needle biopsy in the diagnosis of scar endometriomas, are not clear. Imaging procedures help, rather than confirm, in obtaining a differential diagnosis. Ultrasonography is the best and most commonly used investigation for abdominal masses and lower cost. The mass may appear hypoechoic and heterogeneous mass with messy internal echoes. FNAC was reported in some studies for confirming the diagnosis.[] However, FNAC cytology is a liable method to make the diagnosis of scars, and surgeons must be aware of some diagnosis such as inguinal hernia and reimplantation of potential malignancies during process. Histology is the hallmark of diagnosis. It is satisfied if endometrial glands, stroma, and hemosiderin pigment are seen.[] Local wide excision, with at least a 1 cm margin, is accurate treatment choice of scar endometriosis also for recurrent lesions. Recurrence of scar endometriosis seldom happens with only a few cases reported.

Scar endometriosis is the possible first diagnosis in a mass located close to the incision line with a history of obstetric and gynec operation, increasing pain or discomfort during menstruation. Although malignant transformation of scar endometriosis is exceptionally rare, total surgical excision is the best option for both diagnosis and treatment and to prevent surgical recurrences. The literature recommends thorough cleaning, irrigation with saline, and closure of abdominal wound will prevent scar endometriosis. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

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