Background: Ectopic ovarian tissue is a rare entity that may be encountered at laparoscopy. We present the case of uterovesical pouch ectopic ovary in a 50 year old woman and a review of the literature.
Case: a 50-year-old nulliparous woman presented with a 2-month history of worsening central pelvic pain with associated urinary frequency. She had a history of a laparoscopy and excision of endometriosis and appendicectomy. Examination revealed a soft abdomen with pelvic fullness. A pelvic ultrasound demonstrated a 10cm multilocular left ovarian cyst anterior to the uterus in the uterovesical pouch, with a normal right ovary. Tumour markers were unremarkable.
She underwent a diagnostic laparoscopy, which revealed a 10cm complex cyst in the uterovesical pouch, with a vascular connection to the left infundibulopelvic ligament with the appearance of an ectopic cystic ovary. There were fine peritoneal vascular communications between the vesical peritoneum and ectopic ovary. The left and right ovaries and tubes were normally sited. She underwent a removal of the ectopic ovary in addition to a left salpingo-oophorectomy.
Histopathology demonstrated a partially infarcted, haemorrhagic ectopic ovary with features consistent with possible endometriosis or serous cystadenoma and a normal left tube and ovary.
Her postoperative course was complicated by urinary retention managed with short term catheterisation and she was discharged on day 2 postoperatively.
Discussion:
Ectopic ovary is an uncommonly encountered condition, with multiple synonymous descriptive terms including supernumerary ovary, accessory ovary or ovarian implant syndrome (1). The cause of ectopic ovaries has been hypothesised as either embryological or acquired. Acquired ectopic ovaries are likely caused by either post-inflammatory or post-surgical transplantation of eutopic ovarian tissue, for example after ovarian torsion or surgery for endometriosis (as may be the case in our report)(2), whilst case reports of fetal ectopic ovaries located in the omentum are hypothesised to be caused by aberrant migration of germ cells during embryogenesis (1).
Reported locations of ectopic ovaries vary, with the pouch of douglas & canal of Nuck being the most common. We have not identified any other reports of ectopic ovaries located in the utero-vesical pouch.
Conclusion: Ectopic ovaries should be included in the differential diagnosis of an abdominal or pelvic mass, even in the presence of bilateral eutopic ovaries.