A case report and literature review: incidental jejunal ectopic pancreatic tissue in an emergency bowel exploration for suspected intussusception.

Heterotopic pancreas (HP) is defined as pancreatic tissue which is an anatomically separate entity from the main pancreas and free from the organ's vascular or ductal continuity. Most cases of HP are asymptomatic and are diagnosed incidentally upon laparotomy or on autopsy. The diagnosis of HP can be extremely difficult. A few imaging modalities which include Magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP) may show characteristic features of HP. However, definitive diagnosis is made by histopathology. Conversely, these modalities may not differentiate a malignant neoplasm from a benign mass. Surgical excision is thought to be curative for HP. In this case report, we present a 62-year-old female with acute myelocytic leukemia on induction chemotherapy who developed abdominal pain during her hospital admission and was referred to the general surgery department. Abdominal computed tomography (CT) was done and showed signs of small bowel obstruction, perforation, and overlapping jejunoileal segments suggestive of intussusception. Upon surgical exploration two small bowel perforations were repaired, one iatrogenic and one pathological. On bowel run a jejunal mass was found, excised, and upon histopathology confirmed to be a mixed endocrine and exocrine heterotopic pancreatic choristoma. Definitive diagnosis of heterotopic pancreatic tissue is made by histopathology, and surgical excision is potentially curative. In conclusion, we recommend excising HP if found incidentally upon surgery as the diagnosis of HP and exclusion of neoplasm may not be possible without a histological specimen.