Biliary cystadenoma masquerading as an adnexal cyst in pregnancy

The aetiological diagnosis of cystic masses detected on routine ultrasound during pregnancy can be challenging. Unless approached cautiously with a detailed history and adequate use of imaging techniques, misdiagnosis of these cystic masses are not uncommon. Cystic masses diagnosed during pregnancy are mostly of ovarian origin; however, other non-ovarian cystic masses are also detected incidentally or at laparotomy/laparoscopy. We report a rare case of ruptured biliary cystadenoma in a pregnant woman diagnosed at emergency laparotomy. She was taken up for surgery with a provisional impression of ruptured adnexal cyst. However, the cyst was found to be arising from the liver and the histology of the cyst wall was reported as biliary cystadenoma.