Vulvar Endometriosis by Suspected Spread Via the Round Ligament

Abstract

Study Objective To present a rare case of vulvar endometriosis by suspected spread through the round ligament and review the literature regarding vulvar endometriosis. Design Case report. Setting Tertiary care hospital. Patients or Participants One patient. Interventions Patient with a painful 4 × 3 cm well-circumscribed, subcutaneous mobile mass on the left labia majora deep in the subcutaneous tissue with no overlying skin changes was worked up with CT-guided IR core biopsy that revealed endometriosis. Pelvic MRI revealed a fibroid uterus and 3.8 × 2.6 × 3.1 cm infiltrative soft tissue mass within the left mons pubis extending into the superior aspect of the left labia majora. The mass was noted to be contacting the distal aspect of the round ligament with resultant cyst in the canal of Nuck. Patient underwent laparoscopic myomectomy and local excision of the left vulvar mass for management. Measurements and Main Results Operative findings were consistent with endometrioma in the left vulva and endometriotic implant on the left round ligament at the insertion site into the inguinal canal. Pathology of both the left vulvar mass and excised left round ligament lesion revealed endometriosis. We suggest direct spread via the round ligament as the source of patient's vulvar endometriosis given these findings. Conclusion Spontaneous perineal and vulvar endometriosis is extremely rare, but in cases of clinically suspected vulvar endometriosis, the round ligament should be considered as the potential route of disease spread. Endometriosis should be suspected in extrapelvic lesions with observed cyclic response to the menstrual cycle and considerations should be given for diagnostic laparoscopy to look for pelvic disease in these cases. To present a rare case of vulvar endometriosis by suspected spread through the round ligament and review the literature regarding vulvar endometriosis. Case report. Tertiary care hospital. One patient. Patient with a painful 4 × 3 cm well-circumscribed, subcutaneous mobile mass on the left labia majora deep in the subcutaneous tissue with no overlying skin changes was worked up with CT-guided IR core biopsy that revealed endometriosis. Pelvic MRI revealed a fibroid uterus and 3.8 × 2.6 × 3.1 cm infiltrative soft tissue mass within the left mons pubis extending into the superior aspect of the left labia majora. The mass was noted to be contacting the distal aspect of the round ligament with resultant cyst in the canal of Nuck. Patient underwent laparoscopic myomectomy and local excision of the left vulvar mass for management. Operative findings were consistent with endometrioma in the left vulva and endometriotic implant on the left round ligament at the insertion site into the inguinal canal. Pathology of both the left vulvar mass and excised left round ligament lesion revealed endometriosis. We suggest direct spread via the round ligament as the source of patient's vulvar endometriosis given these findings. Spontaneous perineal and vulvar endometriosis is extremely rare, but in cases of clinically suspected vulvar endometriosis, the round ligament should be considered as the potential route of disease spread. Endometriosis should be suspected in extrapelvic lesions with observed cyclic response to the menstrual cycle and considerations should be given for diagnostic laparoscopy to look for pelvic disease in these cases.