VP59.37: Ectopic pregnancy masquerading as an ovarian cyst

A 32-year-old woman attended the Emergency Department with a week of constant left iliac fossa (LIF) pain and vaginal spotting for a month. She had a background of glioblastoma multiforme which was resected and treated with radiotherapy and ongoing chemotherapy. Outpatient imaging prior to presentation showed a 5.2cm complex left ovarian cyst and a bilobed cystic focus in the right ovary. Blood tests and tumour markers were unremarkable except for serum hCG of 31. Pelvic ultrasound in clinic showed a normal right ovary and well circumscribed unilocular cyst in the left ovary measuring 30x29x43mm with mixed echogenicity, hyperechoic and ground glass material without internal vascularity. It was classified as a benign ovarian lesion (using the IOTA criteria) and thought to represent a haemorrhagic cyst. Repeat ultrasound 6 weeks later showed a left multilocular ovarian cyst with thickened hyperechoic septations, anechoic fluid and hyperechoic dots/lines. The previous diagnosis of haemorrhagic ovarian cyst seemed less likely due to the 6 week interval, and other ovarian pathology such as dermoid cyst was considered. Due to ongoing LIF pain, surgery was recommended. Intraoperatively, a 4cm left fallopian tube mass was found with adhesions to the left paracolic gutter. Both ovaries and the right fallopian tube appeared normal. Peritoneal washings were collected. A left salpingectomy was performed. The histological findings were consistent with tubal ectopic pregnancy undergoing organisation. The peritoneal washings were normal. Postoperative period was uneventful. This case demonstrates the ultrasound features of a resolving tubal ectopic pregnancy that was mistaken for an ovarian lesion, following unintentional treatment with chemotherapy. Ectopic pregnancy is always an important diagnosis to consider when hCG is positive. Contraception counselling and early pregnancy risks for women of reproductive age receiving chemotherapy are vitally important.