A National Survey of Umbilical Endometriosis in Japan.

STUDY OBJECTIVE: To identify the clinical presentation, diagnostic evaluation, operative or medical management, and postoperative recurrence of umbilical endometriosis. DESIGN: A retrospective national survey. SETTING: Obstetrics and Gynecology and Plastic Surgery Departments at a teaching hospital in Japan. PATIENTS: Patients with umbilical endometriosis or malignant transformation. INTERVENTIONS: A national survey was conducted to identify and evaluate cases of umbilical endometriosis or malignant transformation documented between 2006 and 2016. MEASUREMENTS AND MAIN RESULTS: The following were evaluated for each patient: age at diagnosis, body mass index, medical history, presence of extragenital endometriosis, surgical history, symptoms, imaging modalities, surgical therapy, hormonal therapy, follow-up period, postoperative recurrence, and time to recurrence. Ninety-six patients were identified with pathologically diagnosed benign umbilical endometriosis. The patients frequently had swelling (86.5%), pain (81.3%), or bleeding (44.8%) in the umbilicus. Sensitivity was 87.1% for physical examination, 76.5% for transabdominal ultrasonography, 75.6% for computed tomography, and 81.8% for magnetic resonance imaging. The cumulative recurrence rate was 1.34% at 6 months, 6.35% at 12 months, and 6.35% at 60 months after surgery. Importantly, there was no recurrence after wide resection including of the peritoneum (0 of 37 cases). The efficacy of dienogest (an oral progestin), gonadotropin-releasing hormone agonists, and oral contraceptives was 91.7%, 81.8%, and 57.1%, respectively. Finally, 2 cases of malignant transformation were identified. CONCLUSION: There was a low recurrence rate following surgery, and hormonal treatment is an option, although the current findings suggest surgical therapy as the first choice of treatment for umbilical endometriosis.