Urachal adenocarcinoma incidentally discovered in a young woman at elective caesarean section

Urachal adenocarcinoma is a rare non-urothelial malignancy that represents only 0.5% of all vesical cancers. Urachal adenocarcinoma most commonly occurs in the 5th to 7th decade. We describe a case of a 35-year-old woman (G3P1) who presented at 20 weeks pregnancy with two episodes of post-coital bleeding. Ultrasound demonstrated a uterine mass measuring 59×43×56 mm, presumed to be a leiomyoma. The decision was made to proceed to caesarean section at 38 weeks, given the progression of the presumed leiomyoma. A 2 cm bladder dome mass was incidentally discovered at the time of the caesarean section and an urgent intraoperative urology consult was sought. Resultantly, the bladder mass was dissected to the dome, and pathology returned urachal adenocarcinoma. This case report considers the treatment decisions involved when faced with urachal adenocarcinoma and reviews the literature surrounding this rare malignancy.