Heterotopic gastrointestinal cyst mimicking chronic cholecystitis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Heterotopic gastric mucosa is described almost everywhere in the gastrointestinal tract, from the oral cavity to the rectum. The occurrence of heterotopic gastric tissue in the gallbladder is rare. A choristoma can be defined as a new growth developing from a displaced anlage not normally present in the anatomical site where it developed. We present an extremely uncommon case of a cyst (choristoma) attached to the gallbladder, which contained gastric and intestinal mucosa.</p> <p>Case presentation</p> <p>A 33-year-old woman was hospitalized with clinical symptoms of chronic cholecystitis. The laboratory findings were within the normal range. Abdominal ultrasonography revealed a thickened gallbladder wall and a stone in the cystic duct was suspected. In the course of laparoscopic cholecystectomy, a cyst was visualized in the vicinity of the duct and the gallbladder neck. Microscopic examination of the removed cyst revealed evidence of gastric, duodenal and small-intestinal mucosa. The immunohistochemical study revealed many endocrine cells, which were positive for several endocrine cell markers such as chromogranin, serotonin, gastrin and so on. It can be inferred that the observed cyst had arisen from the foregut early in the development of the gastrointestinal tract.</p> <p>Conclusion</p> <p>The presence of endocrine cells together with epithelial cells supports the hypothesis that these had developed simultaneously, and that the endocrine cells had probably supported the development of the epithelial cells by the release of hormones and growth factors. To the best of the authors' knowledge, this report is the first to report a gastrointestinal cyst choristoma with endocrine cells in the region of the cystic duct and gallbladder.</p

Distribution of serotonin positive mast cells in the intrapulmonary airways of rats

Based on the scarce information about the expression of serotonin by mast cells in normal rat lung, we aimed to describe in detail the distribution of these cells in the wall of bronchi and bronchioles, as well as in the interalveolar septa. To visualize serotonin-positive mast cells a toluidine blue staining was performed immediately after the immunohistochemical staining on the same sections. Thus, we estimated the density of mast cell in different layers of intrapulmonary airways and in alveolar parenchyma. A reduction of mast cell numbers from bronchi to bronchioles, and then to alveolar septa was detected. In conclusion, detailed information about the density of serotonin positive mast cells in the layers of the wall of intrapulmonary airways and alveolar parenchyma is presented. Our findings confirm the role of these cells as one of the main sources of serotonin, which participate in maintaining the homeostasis in the lung