Rectal perforation due to malignancy as a rare cause of acute abdomen in a third trimester pregnant patient: a case report

Anatomical and physiological changes during pregnancy may complicate diagnosis and treatment. While the cause of non-obstetric acute abdomen is encountered in one in 500 pregnancies, the most common one may be acute appendicitis. The incidence of colorectal cancer (CRC) during pregnancy is 0.002%. Common symptoms, such as abdominal pain, nausea, vomiting, and changes in bowel movements, are often observed in a regular pregnancy. Thus, most colorectal cases are overlooked and diagnosed in advanced stages associated with a poor prognosis. This case report presents a 31-year-old female patient at 37 weeks of gestation who applied with an acute abdomen, underwent emergency explorative laparotomy, had a 2 cm perforation detected in the rectum, and was referred to neoadjuvant chemo-radiotherapy due to perforation due to malignancy detected in the examinations performed in the postoperative follow-up. The relevant literature notes that colorectal cancer is rarely seen among expectant mothers. It should be suspected in the diagnosis among patients with gastrointestinal complaints for whom conservative treatment has failed. It should also be noted that bowel perforation, a rare complication of colorectal cancer, may also be present in emergency department applications with an acute abdomen.