Tubal endometriosis mimicking an ectopic pregnancy.

A 34 year old lady presented with a one year history of primary infertility, and irregular cycles. Her luteal phase progesterone was low, consistent with anovulation. Her hormone profile was otherwise normal. A semen analysis was normal. A pelvic ultrasound showed polycystic ovaries and hysterosalpingogram revealed a normal uterine cavity with free fill and spill from both tubes. She was commenced on clomiphene. Follicular tracking and luteal phase progesterones confirmed ovulation on treatment. As she failed to conceive after 6 months of treatment, she was booked for laparoscopic ovarian drilling. At laparoscopy, the surface of the right tube was swollen by a bluish mass, measuring 2 by 2 cm, mimicking an ectopic pregnancy. There was evidence of yellowbrown endometriotic patches on the uterosacral ligaments and in both ovarian fossa. Dye test confirmed luminal patency. The routine preoperative pregnancy test was negative. Hence a diagnosis of an atypical endometriotic deposit on the tube was made. Ovarian drilling was done as planned. A first day postoperative serum beta-HCG was negative.