|Year : 2019 | Volume
| Issue : 4 | Page : 220-222
Extraluminal heterotopic pancreatic tissue: An unusual finding
Asim Ahmed, Raga Dilip, Ali Khammas, Yousif Eltayeb
Department of Surgery, Rashid Hospital, Dubai, UAE
|Date of Submission||03-Feb-2019|
|Date of Acceptance||14-Apr-2019|
|Date of Web Publication||11-Nov-2019|
Rashid Hospital, Dubai
Source of Support: None, Conflict of Interest: None
Heterotopic pancreas is defined as pancreatic tissue outside usual anatomic location of the pancreas. The most common location is in the submucosa of the proximal part of the gastrointestinal tract, namely stomach, duodenum, and jejunum. Less commonly, other locations have been reported like the mesentery. It usually presents as an incidental finding during the investigation or operation for acute abdomen. We here present a case of unusual heterotopic extraluminal pancreatic tissue found as scattered multiple tiny spots on the surface of the distal small bowel and its mesentery detected during a laparoscopic appendectomy. A finding that we believe has not been reported before.
Keywords: Ectopic pancreas, extraluminal pancreatic tissue, heterotopic pancreas
|How to cite this article:|
Ahmed A, Dilip R, Khammas A, Eltayeb Y. Extraluminal heterotopic pancreatic tissue: An unusual finding. Hamdan Med J 2019;12:220-2
| Introduction|| |
Heterotopic pancreas (HP), also referred to as ectopic pancreas, aberrant pancreas, or choristoma, is defined as the presence of pancreatic tissue in ectopic sites, which lacks an anatomic and vascular continuity with the main body of the orthotopic pancreas., Many investigators have agreed that the anomaly is antenatal in origin, but the exact mechanism has not been elucidated, and the exact embryologic basis of HP is unknown. However, three theories have been postulated. The most widely accepted theory is the misplacement theory, which states that deposits of pancreatic tissue are “dropped” into the developing gastrointestinal (GI) system. The theory is most appealing as it explains the frequent location of heterotopic pancreatic tissue (HPT) in the primitive foregut.,, The two other theories are the metaplastic and the totipotent theory. The metaplastic theory maintains that HPT is due to abnormal differentiation of multipotent endodermal cells in situ or differentiation of mature intestinal epithelial cells during adult life as a result of inflammation. The transplantation theory suggests that HPT is due to the adhesion of embryonic pancreatic cells to neighboring structures during the rotation of normal or abnormal pancreatic primordia. This theory can account for the much rarer cases of omental, mesenteric, or other HPT as in our case. Evidently, no single theory can explain all cases. Although pancreatic heterotopia is one of the most common heterotopias within the GI system, it still constitutes a relatively uncommon entity with prevalence at autopsy studies ranging from 0.6% to 13.7%., Jean-Schultz first reported HP in 1729, when it was found in an ileal diverticulum. We here report a case of a 20-year-old male who was shown to have extraluminal HPT found as scattered tiny nodules on the surface of the distal small bowel and its mesentery, a condition to the best of our knowledge that has not been previously reported.
| Case Report|| |
A 20-year-old man was admitted to Rashid Hospital, UAE, with symptoms, suggestive of acute appendicitis, supported by clinical examination, confirmed by computed tomography (CT) abdomen and pelvis, which revealed a fluid-filled thick appendix (11.5 mm) with an enhancing wall and no other abnormalities.
The patient underwent laparoscopic appendectomy. Intraoperatively, an inflamed and mildly suppurative appendix was seen with a healthy base and cecum. However, generalized hyperemia of the small bowel was also observed with a few scattered tiny tissue spots seen over the surface of the distal small bowel and mesentery [Figure 1], [Figure 2], [Figure 3].
|Figure 1: Scattered areas of small hyperchromatic tissue within the abdominal cavity|
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Appendectomy was performed, and the small bowel was run to look for any abnormalities or pathology. Only tiny tissue spots found scattered on the surface of the bowel and mesentery associated with bowel hyperemia. The appendix and a sample of the scattered intra-abdominal tissue spots were sent separately for histopathology.
Postoperatively, the patient did well and his hospital stay was uneventful. The patient was discharged on the 2nd postoperative day. The histopathologic examination of the appendix showed an acute suppurative appendicitis; however, the scattered tissue histopathology [Figure 4] showed heterotopic exocrine pancreatic tissue.
|Figure 4: Histopathology of the scattered tissue showing (heterotopic) exocrine pancreatic tissue|
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| Discussion|| |
HP most commonly occurs within the submucosa of stomach, duodenum, and jejunum. The incidence was reported as once in every 500 upper abdominal operations.
Moreover, extraluminal HPT with location outside the foregut is a rarity. Some case reports have described locations in the bowel mesentery.,,, In some reports, abdominal CT and magnetic resonance imaging have documented the presence of HPT in jejunum mesentery but without histopathology documentation. The case we describe differs from other reported cases in its unique location as scattered tissue spots on the surface of the distal small intestine and its mesentery [Figure 1], [Figure 2], [Figure 3]. This finding has not been described in literature.
HPT is usually an incidental finding; and therefore, patients very rarely present with symptoms. Preoperative diagnosis of this rare finding might be difficult to establish due to nonspecific features, and definitive diagnosis is only possible by histopathological examination., This is in contrary to the situation when dealing with the diagnosis of ectopic gastric mucosa, which could be diagnosed by the Tc99m scanning (Meckel's scan). If a patient with ectopic pancreatic tissue is symptomatic, the most commonly encountered symptoms are chronic abdominal pain, chronic pancreatitis, and GI bleeding. In our case, the patient was In his twenties in contrast to the usual cases where the patients are mostly in their fifth or sixth decades. HPT is also more frequently diagnosed and encountered in males more than females. Surgical resection of HP should be performed in symptomatic patients after more common causes of abdominal complaints such as peptic ulcer disease, gastroesophageal reflux disease, and biliary disease have been ruled out. Asymptomatic patients are commonly diagnosed incidentally during the investigation of abdominal pain or operation for other reason. Patient with HTP tissue who are incidentally diagnosed and are asymptomatic should remain under medical surveillance and do not usually require surgical resection until they are symptomatic.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]