Retroperitoneal adenocarcinoma of unknown origin presenting as a rare cause of obstructed labor.

Background: Metastatic retroperitoneal adenocarcinoma presenting as obstructed labor is extremely rare.

Case: An unbooked 35-year-old multipara came to our casualty in obstructed labor at 38 weeks of pregnancy. A palpable retroperitoneal mass was found behind the gravid uterus and cervix after delivery of a live baby during emergency cesarean section. Needle biopsy was taken from the mass and abdomen was closed due to nonavailability of frozen section facility at night. Post cesarean section CT scan confirmed the pelvic mass, which was subjected to open biopsy. A diagnosis of retroperitoneal adenocarcinoma with an unknown primary was made based on histopathology and a negative workup for the possible primary sites. Patient was treated successfully with chemotherapy and did not show recurrence for last 2 years of follow-up.

Conclusion: Surgeons should be aware of this extremely rare entity and it highlights the importance of proper antenatal care to pick up such pathology at an early stage by careful examination and ultrasound to minimize the morbidity and mortality. We also suggest frozen biopsy in a suspected pelvic mass during surgery and early cesarean section to avoid the complications of obstructed labor in such advanced stages of malignant tumor.