Intestinal intussusception caused by intestinal duplication and ectopic pancreas is extremely rare in the clinic and has not been reported previously.

A 29-year-old man was admitted to the hospital for chronic abdominal pain and bloating. The preoperative diagnosis was intestinal obstruction and intussusception. Then, laparotomy, partial small intestinal resection and extraintestinal decompression were performed. Postoperative pathology confirmed intestinal duplication and ectopic pancreas. After surgery, the patient recovered well with no complications. No recurrence was observed after more than 5 mo of follow-up.

We report a new case of a young male with intussusception caused by intestinal duplication and ectopic pancreas. Surgery is the main treatment for these conditions. This study aimed to raise awareness and provide information to improve the clinical management of this rare yet serious condition.

Intestinal intussusception refers to intestinal tube insertion into the connected intestinal lumen, which causes obstruction of the intestinal contents. Adult intussusception only accounts for 5% of the total incidence[1]. The average age of adult patients is 50 years, and the male-to-female ratio is 1:5[2]. Adult intussusception has no specific clinical manifestations and lacks the classic triad of pediatric intussusception symptoms: abdominal pain, vomiting, and jam-like stool. Abdominal computed tomography (CT) is considered the most useful examination, but most specific causes still require intraoperative detection or postoperative pathology for clarification. Ninety percent of adult intussusception is caused by tumors, polyps, diverticulum, etc.[3-6]. Thus, 70% to 90% of adult intussusception requires surgical treatment[7]. However, to date, there are no case reports on intussusception caused by small intestinal duplication and ectopic pancreas.

We report a new case of a young man with intussusception caused by intestinal duplication and ectopic pancreas. Informed consent for the publication of these data was obtained from the patient.

The following diagnoses were made: Intestinal obstruction, intestinal duplication and ectopic pancreas, and intussusception.

The patient underwent emergency exploratory laparotomy, partial small intestinal resection and extraintestinal decompression.

During the operation, the proximal small intestine was found to be inserted into the distal small intestine on the ileum approximately 80 cm away from the ileocecal valve. The lesion length was approximately 20 cm, and the proximal small intestine was dilated to a diameter of approximately 8 cm. The distal small intestine was empty, and the small intestine at the site of intussusception was edematous. Some of the intestinal wall was thickened and hardened, resulting in complete obstruction of the intestinal cavity. Exploration and manual reduction of a mass measuring approximately 3 cm × 2.5 cm at the site of intussusception were difficult. Small intestinal tumors, intestinal intussusception and intestinal obstruction were considered. Partial small intestinal resection and extraintestinal decompression were performed.

The patient recovered well with no complications. No recurrence was found after more than 5 mo of follow-up.

Intussusception is a special form of intestinal obstruction, accounting for approximately 1%-5% of cases[1]. The exact cause of approximately 8%-12% of adult intussusception is unclear[1,7,8]. Any intestinal disease that changes the normal peristalsis of the intestine increases the risk of intussusception[9]. Adult intussusception is often secondary to intestinal tumors, polyps, diverticulum, etc. Therefore, for suspected adult intussusception patients, digestive tract radiography, CT, magnetic resonance imaging and other examinations should be actively performed to clarify the etiology, and active surgery is needed to treat the primary disease and relieve the obstruction. For patients with adult intussusception that can be reduced, subsequent resection of the organic lesions remains the preferred treatment.

Intestinal duplication and ectopic pancreas are two independent congenital defects. The incidence of ectopic pancreas according to autopsy reports is 0.5%-13%[10]. The etiology of ectopic pancreas is still unclear. Studies have shown that during embryonic development, pancreatic primordia adhere to or penetrate the intestinal wall of the embryo and continue to develop and form in various abnormal locations with the movement of intestinal transposition[11,12]. Ectopic pancreas is mainly composed of pancreatic duct and acinar tissue and usually lacks islet tissue. There are no anatomical or vascular connections between the ectopic pancreas and normal pancreas[13]. It most commonly occurs in the duodenum but can also appear in the jejunum and, rarely, in the ileum[14]. Ectopic pancreas is generally considered asymptomatic[15]. In a few case reports, intestinal obstruction, abdominal pain and bleeding were also mentioned[16,17]. Due to the diverse locations and lack of specific lesions, early ectopic pancreas diagnosis is difficult, easily leading to misdiagnoses or missed diagnosis. We searched the literature on PubMed for adult intussusception and ectopic pancreas, and the results are summarized in Table 1.

The incidence rate of intestinal duplication is 1 in 10000 newborns, and it is rare in adults[18]. We retrieved the literature on adult intussusception caused by intestinal duplication from PubMed, and the publications are listed in Table 2. The differences between intestinal duplication and Meckel’s diverticulum are as follows: (1) Intestinal duplication shares a blood supply with the surrounding intestine, while diverticulum has an independent blood supply; and (2) well-developed smooth muscle is present in intestinal duplication but not in Meckel’s diverticulum[19]. Studies suggest that there is a direct communication hole between intestinal duplication and the normal intestinal wall for unknown reasons[20,21]. With the closure of the hole, the muscular layer becomes discontinuous, and feces form a mucosal bridge after passing through the hole, which leads to the occurrence of adult intussusception.

Although adult intussusception, ectopic pancreas and intestinal duplication have been reported separately, our case was unique, as intussusception caused by intestinal duplication and heterotopic pancreas has not been reported previously.

In this case, the patient had been treated in many hospitals for repeated abdominal pain and received symptomatic treatments, such as fluid infusion and pain relief. However, because the fundamental cause of the disease was not determined, the symptoms persisted, and intussusception inevitably occurred, leading to complete intestinal obstruction. Therefore, we speculate that due to the abnormal anatomical position, when intestinal duplication is combined with ectopic pancreatic tissue, the ectopic pancreatic tissue is accompanied by the continuous growth of adipose tissue. Because of the compensatory ability of the body, increased intestinal peristalsis occurs, resulting in intussusception and complete intestinal obstruction. Therefore, early correct diagnosis and timely treatment are critical for adult intussusception.

This is the first reported case of intestinal intussusception caused by intestinal duplication and ectopic pancreas. Therefore, intestinal duplication and ectopic pancreas should be considered in the differential diagnosis of intussusception. Although modern diagnostic technology has greatly progressed, diagnosis of intestinal duplication and ectopic pancreas remains difficult. Definitive diagnosis usually depends on postoperative pathology.