Aberrant pancreas is a heterotopy of pancreatic glandular tissue in the wall of the stomach, intestines or other abdominal organs. The anomaly is characterized by scant clinical manifestations with a predominance of dyspeptic disorders. Complicated forms of pathology manifest as a symptom complex of “acute abdomen”, gastrointestinal hemorrhages. Diagnostics is based on instrumental methods: ultrasound, radiography with oral contrast, EGD. The diagnosis is confirmed by a pathomorphological examination of the biomaterial. Asymptomatic anomalies do not require treatment, with complications, surgical interventions are mainly resorted to.
Q45.3 Other congenital anomalies of the pancreas and pancreatic duct
In the medical literature, the anomaly has a number of synonyms: an additional pancreas, choristoma, ectopia of the pancreas. The disease is the most common malformation of the pancreas and is detected in 0.2% of patients during surgical interventions on the abdominal organs. According to autopsies, heterotopia occurs in 1.3% of people in the population. The anomaly is 2 times more common in men. It is mainly detected by chance at the age of 40-70 years during an instrumental examination of the digestive system.
Reasons of aberrant pancreas
In modern gastroenterology, there is no consensus on etiological factors. Most scientists claim that pathology occurs in the prenatal period with the combined influence of several causes. The most likely of them include spontaneous genetic mutations, infections suffered by the mother during pregnancy. Less often, the connection of aberrant pancreas with taking medications with a teratogenic effect is determined.
Risk factors for the development of choristoma include smoking, alcohol and drug use by a pregnant woman. The likelihood of the disease increases when living in ecologically unfavorable regions, exposure to ionizing radiation on a child in the embryonic period of intrauterine development. The risk of aberrant tissue formation increases with genetic predisposition — the presence of various anomalies in the closest relatives.
The exact mechanism of anomaly formation is still unclear. It is most likely that the aberrant tissue is a manifestation of atavism in ontogenesis. Violation of the laying and differentiation of the pancreas during antenatal development leads to an abnormal location of part of the organ. The formed accessory gland has an isolated blood supply and innervation, functions independently of the bulk of glandular cells.
Classification of aberrant pancreas
Choristomas differ in anatomical localization. Aberrant gland tissue can be located in various organs:
- duodenum (31.83%);
- stomach wall (31.46%);
- jejunum (21.7%);
- ileum (9.36%);
- mesentery (3.37%);
- bile ducts (1.49%).
Among gastric aberrant pancreas, the majority (58.2%) is located in the pylorus. According to macroscopic signs, there are 4 forms: nodular, polypous, diffuse and mixed.
Symptoms of aberrant pancreas
The vast majority of heterotopias are asymptomatic and are detected accidentally during gastroenterological diagnostics, operations in the abdominal cavity. Symptoms usually occur with a complicated course of the disease and are determined by the localization of the aberrant pancreas. The initial signs are nonspecific dyspeptic disorders: heaviness in the stomach after eating, nausea, instability of the stool.
The clinical manifestation of a large aberrant gland is possible already in early childhood. It bothers regurgitation after eating, from time to time there is abundant vomiting with curdled milk or partially digested food. Children eat poorly, slowly gain weight, lag behind in physical development. In adulthood, the anomaly usually occurs under the guise of chronic gastritis, pancreatitis, cholecystitis.
A typical symptom of complicated forms of pathology is severe abdominal pain of various localization. Vomiting with impurities of mucus and bile is often found. When the bile ducts are affected, discolored feces are released. Rarely, the aberrant pancreas manifests gastrointestinal bleeding, which is manifested by bloody vomiting or melena.
Often, with choristoma, stenosis of the pyloric part of the stomach is observed, which makes it difficult for food to move into the small intestine. In the compensated stage, nutrition and energy metabolism are practically not disturbed. At the stage of decompensation, exhaustion of patients, anemia and signs of vitamin deficiency are characteristic. With the location of aberrant tissue in the small intestine, there is a possibility of developing acute intestinal obstruction requiring urgent surgical care.
The accessory pancreas is often subject to inflammation and necrosis. Aseptic or purulent lesion of aberrant tissue begins, which is fraught with perforation of the wall of the affected organ. When the vascular walls melt, profuse bleeding may open. The presence of heterotopia increases the risk of peptic ulcer disease, mechanical jaundice. The most dangerous consequence of an undiagnosed choristoma is malignancy.
Detection of aberrant glandular tissue by standard methods of investigation is difficult, since the abnormal formations look like a benign tumor. To verify the diagnosis, a gastroenterologist prescribes invasive techniques followed by histological confirmation. If pancreatic heterotopia is suspected, the diagnostic search includes the following studies:
- Ultrasound of the abdominal cavity. With sonography, it is possible to detect aberrant tissue only of a large volume, which is visualized as hyperechoic areas in atypical places. Ultrasound results do not allow to establish the nature of the volume formation. Dopplerography is recommended to assess the blood flow in the accessory pancreas.
- Radiological methods. During radiography of the passage of barium in the gastrointestinal tract, heterotopia looks like a rounded filling defect. With a complicated form of the disease, a niche or a spot of barium is detected against the background of the defect. The aberrant pancreas can be seen with computed tomography OBP.
- EGD. During endoscopic examination, choristomas localized in the stomach or the initial parts of the duodenum are clearly visible. They have the form of polyps or individual nodes, on the surface of which there is often the mouth of the excretory duct.
- The study of biopsies. Morphological analysis of a tissue sample is crucial in the diagnosis by a chorister. According to the histological structure, the additional glandular tissue can completely correspond to normal or contain separate elements — islets of Langerhans, acinuses or excretory ducts.
- Laboratory methods. The analyses are of an auxiliary nature. To assess the external secretory function of the pancreas, the level of amylase, lipase and trypsin in the blood is determined. The amount of fecal elastase is examined in fecal samples. Fasting glucose is measured in the blood, a glucose tolerance test is performed.
Treatment of aberrant pancreas
In gastroenterology, there is a successful experience in the use of analogues of the hormone somatostatin. These drugs inhibit the proliferation of glandular cells, prevent the transformation of benign heterotopia into a tumor process. With insufficient exocrine function of pancreatic tissue, enzyme replacement therapy is prescribed. To eliminate unpleasant symptoms, analgesics, choleretic drugs, and prokinetics are used.
In abdominal surgery, the expediency of surgical intervention with an aberrant pancreas remains a subject of scientific debate. With an asymptomatic course and normal functioning of an organ with glandular heterotopia, patients need to be monitored. The possibility of surgery is decided individually for patients with reduced functional activity of the main pancreas.
The absolute indications for performing radical treatment are considered to be complicated variants of an aberrant anomaly. The most economical resection within healthy tissues is recommended. During the formation of pyloric or intestinal stenosis, surgical correction is provided, if necessary, an anastomosis is applied. Choristomas with a high risk of malignancy are subject to mandatory removal.
Prognosis and prevention
Asymptomatic forms of aberrant pancreas do not pose a risk to human health and life, in which case the prognosis is considered favorable. Prognostically unfavorable is the appearance of complications from the stomach, intestines, biliary system, rapid increase in the size of the accessory gland. Given the unclear etiopathogenesis, specific measures of primary prevention have not been developed.