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Case Report

A case report of ectopic pancreas in the ileum incidentally diagnosed during laparotomy for acute colonic diverticulitis

Bigonzi, Eleonora,*; Miconi, Guglielmo; Colozzi, Sara; Coletta, Pietro; Palmieri, Miriam; Ortenzi, Monica; Guerrieri, Mario

Author Information
Il Giornale di Chirurgia – Journal of the Italian Surgical Association: August 2022 - Volume 42 - Issue 2 - p e03
doi: 10.1097/IA9.0000000000000004
  • Open

Abstract

Introduction

Ectopic pancreas (EP) refers to isolated pancreatic tissue found outside the pancreatic frame. It is considered a rather rare congenital anomaly with an incidence of 0.2% during laparotomy and 0.55% to 13.7% in postmortem studies, although the true incidence and prevalence are not well defined, because most individuals are asymptomatic.1,2 It could occur either within the digestive tract or outside it in organs such as liver, spleen, umbilicus, fallopian tube, lung, and mediastinum. The stomach and duodenum are widely considered the 2 most common locations of EP (24% to 43% and 9% to 36% of all cases, respectively). The jejunum is the third most common site (0.5% to 35% of the cases), while ileal EP, including Meckel diverticulum, accounts for 2.8% to 7.5% of the total cases, being the fourth most frequent localization. Other reported anatomic sites of the digestive tract are, for example, colon, appendix, mesentery, esophagus but they are extremely rare.1 Most cases of EP are found incidentally, performing a procedure for another purpose.2 The few symptomatic patients usually experience nonspecific symptoms, which are related to anatomical location and size, while complications secondary to EP are pancreatitis, pseudocyst formation, malignant degeneration, gastrointestinal bleeding, bowel obstruction, and intussusception and they occur as epigastric pain, nausea, and vomiting.3

The preoperative diagnosis of EP is challenging, with limited imaging options.

Surgical excision is potentially curative for EP, and it can provide tissue for histological diagnosis necessary to rule out malignancy; in addiction, surgery may also prevent future complications.2

Case presentation

A 75-year-old woman was admitted for elective surgery to our institution. Past medical history included hypertension, dyslipidemia, SchÖnlein-Henoch purpura, psoriasis, diffuse proliferative glomerulonephritis, gallstones disease, peptic disease, and the patient underwent a hysterectomy and appendectomy. She suffered from colonic diverticulosis for 10 years, but only experienced episodes of recurrent diverticulitis in the last year. Five months before our observation, she was admitted to the Emergency Department and then to the Department of Gastroenterology with a clinical situation consistent with acute diverticulitis. The abdominal CT demonstrated thickening of the intestinal wall of the descending and sigmoid colon, complicated by the presence of microperforation. The general surgery team was consulted and she was scheduled for elective surgery.

A CT virtual colonoscopy, executed 3 months later, revealed severe diverticular disease of the proximal and middle sigmoid colon, that appeared hypertonic with circular musculature hypertrophy, narrowing of the lumen and multiple diverticula. The radiological findings, previously referred to micro perforation, were resolved. There was also a persistently enhanced polypoid lesion (2 cm × 1.5 cm in size) originating from the wall of the proximal ileum which was strongly suspected as being GIST (Gastrointestinal Stromal Tumors) or NET (Neuroendocrine Tumor). A revision of the previous abdominal CT confirmed the presence of the ileal mass, without current increase in dimension. Considering the hypothesis of GIST, we excluded the execution of esophagogastroduodenoscopy or capsule endoscopy, since a laparotomy was planned with an extensive exploration of all the bowel.

The day of the admission for elective surgery, the patient was completely asymptomatic. No significant findings at physical examination; no history of pain or other gastrointestinal symptoms. She underwent an exploratory laparotomy, during which the small jejunal lesion described in CT was identified: a segmental resection of the affected jejunum with end-to-end anastomosis was performed. The mass was gray coloured and slightly thickened in consistency. At abdominal exploration, a severe diverticular disease with wall thickening from the sigmoid colon to the rectal junction, widespread pelvic adhesions as well as gallstone disease were reported requiring adhesiolysis, sigmoidectomy, colorectal mechanical anastomosis, and cholecystectomy. Histopathological analysis of the specimen revealed complete excision of the mass (1.5 cm in size), which was defined as benign pancreatic tissue, located in the deep submucosal and muscular layer of the bowel.

The hospital stay of 9 days was due to a mild delay in canalization. At the last follow up after surgery, the patient was symptom-free. We are planning a PET/CT imaging with 18F-DOPA at 1 year in order to detect other lesions and to avoid an invasive laparotomy, even if the EP is a rare entity usually seen as single lesion and in literature there are not case of simoultaneous presentations.

Discussion

EP tissue can be found anywhere in the alimentary tract and in other sites, but it can be discovered frequently in the stomach, duodenum and jejunum. EP is usually silent, in fact 41% to 66% of it is found incidentally during surgery for other clinical conditions. Studies have shown that 33% to 47% are symptomatic with clinical features depending upon size, location, and association with another disorders.4 Generally, symptoms secondary to EP can be divided into two categories: those associated to the presence of any mass and those specific to pancreatic tissue. The former, which are mainly bowel or biliary obstruction, intussusception and ulceration, are largely determined by the size and location of the masses, while pancreatic tissue related complications are mostly pancreatitis and pancreatic neoplasm.1

The preoperative diagnosis of EP is tricky. There are no biochemical markers able to detect EP.2 Computed tomography is one of the most important radiological examinations of small bowel diseases and it is used for evaluation of EP because it can localize lesions and demonstrate EP, which enhances similarly with the normal pancreatic tissue. Typically, CT images of EP in the gastrointestinal tract show a round or ovular intramural soft tissue mass with smooth or microlobulated margins. The use of capsule endoscopy or double-balloon enteroscopy in the ileum is seldom reported in literature.1 Also magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP) have been proposed by different studies to improve preoperative diagnosis of EP.2

Indubitably, symptomatic cases of EP should be treated aggressively. Segmental small bowel resection and reduction of intussusception, if present, are the treatments of choice. Diverticulectomy can be adopted if the lesion is found inside a diverticulum and the adjacent bowel is intact. Instead, the management of asymptomatic cases is still under debate. Some argue that all cases of EP, symptomatic or not, should be treated.1 When EP is reported during surgery for other abdominal conditions, resection should be performed.4,5 The surgical treatment is safe, effective, and potentially curative, with local excision preferred to radical surgery. Surgery also allows histological diagnosis defining the presence of eventual malignancy and, furthermore, may prevent future complications.2

Conclusions

We present the case of an incidental radiological finding of proximal jejunal lesion, in a 75-year-old woman presenting with colonic diverticulitis. Although this clinical case cannot be considered unique, in literature there are not similar reports of suspected GIST preoperatively, further identified as EP at histological diagnosis. Even if this entity is really rare, we suggest to consider this hypothesis in the differential diagnosis, specially when a preoperative biopsy cannot be performed. Although rare and unlikely, we should take into account that jejunal EP can cause bleeding or jejunojejunal intussusception, that is the most common complication related to jejunal EP. Surgery is safe, effective and potentially curative and should be performed in all cases of EP, symptomatic or not. Surgery also allows histological diagnosis and rules out eventual malignancy.

F1
Figure 1.:
Coronal section on preoperative CT abdomen showing persistently enhanced mass in the proximal ileum.
F2
Figure 2.:
Transverse section arterial phase on preoperative CT abdomen showing persistently enhanced mass in the proximal ileum.
F3
Figure 3.:
Transverse section venous phase on preoperative CT abdomen showing persistently enhanced mass in the proximal ileum.

References

1. Xiang S, Zhang F, Xu G. Ectopic pancreas in the ileum: an unusual condition and our experience. Medicine (Baltimore). 2019;98:e17691.
2. Saeed MF, Verhagen KR, Albinali S, Juma IM. A case report and literature review: incidental jejunal ectopic pancreatic tissue in an emergency bowel exploration for suspected intussusception. AME Case Rep. 2019;3:24.
3. Zhang P, Wang M, Bai L, Zhuang W. A unique case of ectopic pancreas presenting as jejunal malignance. J Surg Case Rep. 2019;2019:rjz217.
4. So HF, Cross TJ, Zonta M. A case report of incidental ectopic pancreatic tissue during laparoscopic appendicectomy. Int J Surg Case Rep. 2018;45:77–78.
5. Hirasaki S, Kubo M, Inoue A, Miyake Y, Oshiro H. Jejunal small ectopic pancreas developing into jejunojejunal intussusception: a rare cause of ileus. World J Gastroenterol. 2009;15:3954–3956.
Keywords:

Ectopic pancreas; Heterotopic pancreas; Incidental; Laparotomy; Jejunum; Risk of malignancy

Copyright © 2022 The Authors. Published on behalf of the Associazione Chirurghi Ospedalieri Italiani and Wolters Kluwer.