Pancreatic and Gastric Heterotopia in the Gallbladder: A Rare Incidental Finding

Abstract

Heterotopic or ectopic tissue is a congenital anomaly, which is defined as the presence of the tissue outside its normal location, without neural, vascular, or anatomic connection with the main body of an organ in which it normally exists. This tissue is usually discovered incidentally and may be asymptomatic or may present with nonspecific gastrointestinal (GI) symptoms. Pancreatic and gastric heterotopia are the two predominantly occurring heterotopic tissues in the GI tract.[12] The prevalence of ectopic pancreatic tissue in the GI tract ranges from 0.6% to 13.7% of autopsy series and it can be present anywhere in the GI tract with the most common localizations being stomach (27.5%), duodenum (25.5%), colon (15.9%), esophagus, and Meckel's diverticulum.[345] It is a rare finding in the gallbladder and its prevalence has not been ascertained due to lack of large-scale studies and systematic review of literature. Similarly, heterotopic gastric tissue is common throughout the GI tract from the tongue to the rectum,[67] but it is extremely rare in the gallbladder with only around 34 cases reported in literature so far, while other cases of different types of heterotopic tissues in the gallbladder such as liver tissue and others such as adrenal and thyroid tissues have been described.[8] The most common presentation of ectopic tissue in the gallbladder is colicky pain in the epigastrium or right upper quadrant sometimes associated with nausea and vomiting. Here, we are presenting two incidentally detected cases, each of gastric and pancreatic heterotopias in the gallbladder.

Keywords: Chromogranin; heterotopia; pancreatic tissue.

Figure 1

Heterotopic pancreatic tissue in the wall of the gallbladder (H and E, ×10). Inset showing few islet cells in heterotopic pancreatic tissue showing immunoreactivity to chromogranin-A (×40)