Heterotopic Pancreatitis

HomeRadioGraphicsVol. 44, No. 1 PreviousNext Cases from the Cooky JarFree AccessHeterotopic PancreatitisMaria L. Brun-Vergara , Pegah Khoshpouri, John Karp, Anne Sailer, Perry J. PickhardtMaria L. Brun-Vergara , Pegah Khoshpouri, John Karp, Anne Sailer, Perry J. PickhardtAuthor AffiliationsFrom the Department of Radiology, The Ottawa Hospital, 1053 Carling Ave, Ottawa, ON, Canada K1Y 4E9 (M.L.B.V.); Department of Radiology, University of Washington, Seattle, Wash (P.K.); Department of Radiology, University of Pennsylvania, Philadelphia, Pa (J.K.); Department of Radiology, Yale New Haven Health, Yale University, New Haven, Conn (A.S.); and Department of Radiology, University of Wisconsin, Madison, Wis (P.J.P.).Address correspondence to M.L.B.V. (email: [email protected], @MariaLuciaBrunV).Maria L. Brun-Vergara Pegah KhoshpouriJohn KarpAnne SailerPerry J. PickhardtPublished Online:Dec 14 2023https://doi.org/10.1148/rg.230167MoreSectionsPDF ToolsAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookXLinked In Heterotopic pancreas is a rare congenital condition in which pancreatic tissue deposits abnormally outside the pancreas (1). Heterotopic pancreas is a migration-type congenital anomaly (1). Although the embryologic mechanism is still unclear, three prevailing theories have been proposed: the misplacement, metaplasia, and totipotent cell theories (1–3). The most widely accepted theory, misplacement, suggests that pancreatic tissue fragments are deposited separately from the main gland during foregut rotation in the developing gastrointestinal system (1,2). Alternatively, the metaplasia theory suggests that endodermal cells migrate to the submucosa and transform into pancreatic tissue, and the totipotent cell theory proposes that intestinal endodermal cells differentiate into pancreatic tissue (1,2). Molecular and genetic abnormalities have also been postulated (3).Heterotopic pancreas is usually discovered incidentally and is typically asymptomatic. However, it may develop any of the complications seen with the orthotopic pancreas. Acute pancreatitis is not always visible clinically or radiologically in the setting of heterotopic pancreas (Fig 1). Typically, there is only mild enzyme elevation due to the small volume of inflamed tissues, and tissue may enhance less avidly when acutely inflamed (1,4). The location of the heterotopic tissue will dictate the site-specific complications and imaging features (Fig 2).Figure 1. Heterotopic pancreas complicated by acute pancreatitis in a 28-year-old woman with abdominal pain and nausea (elevated serum lipase level of 1300 U/L). Axial contrast-enhanced CT images show the normal orthotopic pancreas without evidence of inflammation (white arrow in A, B). A lobulated mass is seen extending off the gastric antrum with a similar appearance to and enhancement as the orthotopic pancreas (arrowhead in C–F), with surrounding fat stranding. Note also a primordial ductlike structure centrally (black arrow in C, D). The most common CT appearance of heterotopic pancreas is an intramural mass with ill-defined microlobulated margins. The attenuation and enhancement characteristics are related to the histologic composition: acinus-dominant lesions demonstrate avid homogeneous enhancement, whereas duct-dominant lesions are hypovascular and heterogeneous after contrast agent administration.Figure 1.Download as PowerPointFigure 2. Medical illustration shows the most common sites of involvement and possible associated complications of heterotopic pancreas. Sites where heterotopic pancreas can be found include the gastrointestinal tract, Meckel diverticulum, mesentery, hepatobiliary system, and spleen, as well as other less common extragastrointestinal locations such as the mediastinum, lungs, fallopian tubes, umbilicus, and omentum (1). Common gastrointestinal locations of heterotopic pancreas include the stomach, duodenum, and proximal jejunum, possibly due to their shared origins from the primitive foregut (1,5). As in orthotopic pancreas, heterotopic pancreas is susceptible to pancreatitis, pseudocyst formation, and pancreatic neoplasms (1,2). Location-related complications include gastrointestinal bleeding, bowel obstruction, and intussusception (1). Paraduodenal pancreatitis likely results from deposited heterotopic pancreas tissue in the medial duodenal wall leading to abdominal pain and duodenal obstruction and can act as a lead point causing intussusception (1,6). Esophageal and gastric lesions may manifest with dysphagia, epigastric pain, gastroesophageal reflux disease, and possible hemoptysis (6). GI = gastrointestinal.Figure 2.Download as PowerPointDisclosures of conflicts of interest.—M.L.B.V. RSNA Across the Americas Travel Award, travel stipend for RSNA 2022 Annual Meeting. P.J.P. Consulting fees from Bracco, Nanox-AI, and GE HealthCare. All other authors have disclosed no relevant relationships.References1. Rezvani M, Menias C, Sandrasegaran K, Olpin JD, Elsayes KM, Shaaban AM. Heterotopic Pancreas: Histopathologic Features, Imaging Findings, and Complications. RadioGraphics 2017;37(2):484–499. Link, Google Scholar2. Kim DU, Lubner MG, Mellnick VM, Joshi G, Pickhardt PJ. Heterotopic pancreatic rests: imaging features, complications, and unifying concepts. Abdom Radiol (NY) 2017;42(1):216–225. Crossref, Medline, Google Scholar3. Liu YM, Shen HP, Li X, Gong JP. Heterotopic pancreas: a clinical analysis of nine patients and review of literature. Am Surg 2012;78(3):E141–E143. Crossref, Medline, Google Scholar4. Sandrasegaran K, Maglinte DD, Cummings OW. Heterotopic pancreas: presentation as jejunal tumor. AJR Am J Roentgenol 2006;187(6):W607–W6095. https://doi.org/10.2214/AJR.05.055 Crossref, Medline, Google Scholar5. Ulrych J, Fryba V, Skalova H, Krska Z, Krechler T, Zogala D. Premalignant and malignant lesions of the heterotopic pancreas in the esophagus: a case report and review of the literature. J Gastrointestin Liver Dis 2015;24(2):235–239. Crossref, Medline, Google Scholar6. Castell-Monsalve FJ, Sousa-Martin JM, Carranza-Carranza A. Groove pancreatitis: MRI and pathologic findings. Abdom Imaging 2008;33(3):342–348. Crossref, Medline, Google ScholarArticle HistoryReceived: June 5 2023Revision requested: June 23 2023Revision received: July 7 2023Accepted: July 12 2023Published online: Dec 14 2023 FiguresReferencesRelatedDetailsRecommended Articles Heterotopic Pancreas: Histopathologic Features, Imaging Findings, and ComplicationsRadioGraphics2017Volume: 37Issue: 2pp. 484-499Case 307: Heterotopic Pancreas in Jejunal MesenteryRadiology2022Volume: 305Issue: 2pp. 490-494Imaging of Drug-induced Complications in the Gastrointestinal SystemRadioGraphics2016Volume: 36Issue: 1pp. 71-87Fluoroscopic Evaluation of Duodenal DiseasesRadioGraphics2022Volume: 42Issue: 2pp. 397-416Omphalomesenteric Duct Anomalies in Children: A Multimodality OverviewRadioGraphics2021Volume: 41Issue: 7pp. 2090-2110See More RSNA Education Exhibits Imaging Of Acute Gastric ConditionsDigital Posters2020Imaging Features Of The Ectopic Tissues With Embryologic Approach For Correct Diagnosis.Digital Posters2021Do You Remember The Meckel Diverticulum?Digital Posters2022 RSNA Case Collection Pancreatic-colonic fistula RSNA Case Collection2021Pancreatic LacerationRSNA Case Collection2021Acute Meckel's diverticulitisRSNA Case Collection2020 Vol. 44, No. 1 Metrics Altmetric Score PDF download