Heterotopic Pancreatic Pseudocyst Radiologically Mimicking Gastrointestinal Stromal Tumor

Heterotopic pancreas is a relatively common variant of foregut embryologic dystopia that can be described as pancreatic tissue found outside the normal anatomic location, being independent from vascular supply of normal pancreas. Having all features of pancreatic tissue except for the major duct structures, this ectopic tissue may be clinically recognized when pathologic changes take place. Inflammation, hemorrhagic or obstructive states, and eventually malignancy-related problems may become a diagnostic challenge for clinician and finally lead to consequences of misdiagnosis. In this article we will discuss a case of heterotopic pancreatic tissue located in gastric cardia, which was diagnosed preoperatively as gastrointestinal stromal tumor.Key words: Ectopic pancreas, Pseudocyst, Gastrointestinal stromal tumor, MisdiagnosisHeterotopic (ectopic) pancreas is defined as the presence of pancreatic tissue in an aberrant site that is not anatomically and vascularly connected to the pancreas proper.^1,2 Ectopic pancreatic tissue is most commonly found in the duodenum (particularly the second portion), ampulla, stomach (prepyloric antrum), and upper jejunum; it can also occur in the liver, biliary tract, Meckel''s diverticulum, and several other sites such as large bowel, spleen, omentum, mediastinum, lung, thyroid, and even brain.^1–6 The heterotopic pancreatic tissue is usually located in the submucosa and/or the muscularis or subserosa.^1,2,4Practically any pancreatic pathology can also occur in the heterotopic pancreatic tissue including acute pancreatitis and neoplastic transformation.^1,4,7,8 Episodes of acute pancreatitis may cause local inflammation and typical pancreatitis-related complications in the host organ. The ectopic pancreatic tissue can lead to ulceration and bleeding in the cases located beneath a mucosa. Being a mass-forming lesion, it may also result in luminal obstruction (particularly in the prepyloric antrum).^1,4Although it is a relatively common congenital anomaly (0.5% to 13% in autopsy series), in most cases heterotopic pancreas remains clinically silent and is found incidentally during surgery or an endoscopic and/or radiological investigation.^1,9 Heterotopic pancreas may be confused with other solid tumors of the host organ.Heterotopic pancreas in the stomach is usually located in the prepyloric area.¹⁰ We report here an unusual case of heterotopic pancreas with a pseudocyst formation in the gastric cardia mimicking gastrointestinal stromal tumor.