Heterotopic Pancreas: Histopathologic Features, Imaging Findings, and Complications

Abstract

Heterotopic pancreas is a congenital anomaly in which pancreatic tissue is anatomically separate from the main gland. The most common locations of this displacement include the upper gastrointestinal tract-specifically, the stomach, duodenum, and proximal jejunum. Less common sites are the esophagus, ileum, Meckel diverticulum, biliary tree, mesentery, and spleen. Uncomplicated heterotopic pancreas is typically asymptomatic, with the lesion being discovered incidentally during an unrelated surgery, during an imaging examination, or at autopsy. The most common computed tomographic appearance of heterotopic pancreas is that of a small oval intramural mass with microlobulated margins and an endoluminal growth pattern. The attenuation and enhancement characteristics of these lesions parallel their histologic composition. Acinus-dominant lesions demonstrate avid homogeneous enhancement after intravenous contrast material administration, whereas duct-dominant lesions are hypovascular and heterogeneous. At magnetic resonance imaging, the heterotopic pancreas is isointense to the orthotopic pancreas, with characteristic T1 hyperintensity and early avid enhancement after intravenous gadolinium-based contrast material administration. Heterotopic pancreatic tissue has a rudimentary ductal system in which an orifice is sometimes visible at imaging as a central umbilication of the lesion. Complications of heterotopic pancreas include pancreatitis, pseudocyst formation, malignant degeneration, gastrointestinal bleeding, bowel obstruction, and intussusception. Certain complications may be erroneously diagnosed as malignancy. Paraduodenal pancreatitis is thought to be due to cystic degeneration of heterotopic pancreatic tissue in the medial wall of the duodenum. Recognizing the characteristic imaging features of heterotopic pancreas aids in differentiating it from cancer and thus in avoiding unnecessary surgery. RSNA, 2017.

Ectopic pancreas: A rare cause of occult gastrointestinal bleeding

“…Preoperative diagnosis of EP is difficult. They appear as mural wall thickening, exophytic or endoluminal enhancing lesions on CT as seen in the present case [ 8 ]. On endoscopy, they appear as a circular to oval submucosal lesion with central umbilication [ 9 ].…”

Acute Clinical Manifestation of Mesenteric Heterotopic Pancreatitis: A Pre- and Postoperative Confirmed Case

“…Most cases of heterotopic pancreas are found in the upper gastrointestinal tract with 70–87% of cases affecting the stomach, duodenum, and jejunum in mostly submucosal localization [ 1 , 5 ]. Less common sites of origin include Meckel diverticulum, ileum, gallbladder, bile ducts, Fallopian tubes, mediastinum, oesophagus, spleen, omentum, and mesentery [ 2 , 5 , 6 ]. Zhang et al [ 7 ] and Henry et al [ 6 ] report the mesenteric manifestation in, respectively, 3.8% and 5.9% of the heterotopic pancreas.…”

Pseudoquiste pancreático intramural gástrico en páncreas heterotópico, una causa infrecuente de retención gástrica. Caso clínico

“…La apariencia tomográfica más común del páncreas heterotópico es una pequeña masa in-tramural ovalada, con márgenes microlobulados y crecimiento endoluminal que puede ser confundida con un engrosamiento parietal neoplásico 1 .…”

“…Chile. gschiappacasse@gmail.com E l páncreas heterotópico o ectópico es una entidad rara, definida como la presencia de tejido pancreático en una ubicación distinta a la habitual, sin continuidad anatómica o vascular con el páncreas y puede ocurrir en cualquier parte del tracto gastrointestinal 1 . En la mayoría de casos el páncreas heterotópico no produce síntomas, pero ocasionalmente puede presentarse como dispepsia, pancreatitis ectópica, hemorragia digestiva alta o como una masa inflamatoria abdominal.…”