S4084 Pushing Out More Than a Baby: Delivery of Rectosigmoid Adenocarcinoma

Introduction: Colorectal cancer (CRC) screening with colonoscopy remains the gold standard for diagnosing benign polyps to malignancies, with well-established guidelines focused on age and risk stratification. CRC in pregnancy is extremely rare, only occurring in around 0.002% of women of pregnancy. This incidence has increased as maternal age is on the rise as well as an increase in early-onset CRC. Symptoms of CRC such as constipation, nausea, or rectal discomfort may be misattributed to normal physiologic changes in pregnancy, potentially delaying diagnosis. We present a patient with an unusual discovery of CRC during labor, highlighting the diagnostic challenges and life-saving potential of incidental discovery. Case Description/Methods: A 30-year-old woman with no past medical history underwent an uncomplicated vaginal delivery. During delivery, she expelled what appeared to be a polyp protruding from the rectum. The 2 cm specimen was sent for pathology review and revealed a tubular adenoma with high grade dysplasia. Subsequent colonoscopy one week later showed internal hemorrhoids and a 2.5 cm polyp in the rectosigmoid region, removed with a cold snare. Pathology revealed an invasive, moderate to poorly differentiated adenocarcinoma arising within a villous adenoma. Serum CEA was 0.5. Staging computed tomography (CT) of the abdomen and pelvis showed no metastatic disease. The tumor was staged as pT1. The patient endorsed intermittent constipation and nausea during her pregnancy but otherwise denied occult bleeding, systemic complaints, or a family history of colon cancer or other GI malignancies. Follow-up surveillance with alternating endoscopic ultrasound and magnetic resonance imaging yielded no disease recurrence. Discussion: There are only a few published cases describing incidental polyp discovery during labor and delivery, and even fewer with an established diagnosis of invasive adenocarcinoma. In this case, the diagnosis was made in a patient without identifiable risk factors and well below the recommended CRC screening age; the malignancy may have otherwise gone undetected, possibly making the discovery life-saving. This case also highlights how normal GI physiology of pregnancy (such as nausea, altered bowel habits) may be easily misattributed, further emphasizing how CRC can remain clinically silent even at invasive stages. Finally, this case highlights the importance of maintaining a high index of suspicion in atypical situations. Malignancy may present in the most unexpected of ways, and vigilance is quintessential to lead to early detection.