Heterotopic pancreas in the common bile duct, with a review of the literature

Insight into gastrointestinal heterotopic pancreas: imaging evaluation and differential diagnosis

Heterotopic pancreas (HP) is an uncommon congenital abnormality in the developmental process of the pancreas, with gastrointestinal heterotopic pancreas (GHP) being the most common HP. The clinical manifestations of GHP may have variable patterns of presentation, dictated by both the anatomic location and the functional ability of the lesion. The most common imaging modality in detecting GHP is computed tomography (CT), while gastrointestinal barium fluoroscopy, endoscopic ultrasonography, and magnetic resonance imaging (MRI) are also applied. The density and enhancement patterns of GHP are consistent with histological classifications. GHP with a predominantly acinar tissue component manifests homogeneous and marked enhancement on CT images, whereas a predominantly ductal GHP presents heterogeneous and mild enhancement. On MRI, the appearance and signal intensity of GHP were paralleled to the normal pancreas on all sequences and were characterized by T1-weighted high signal and early marked enhancement. This article provides a comprehensive review of the histopathology, clinical manifestations, imaging features of various modalities, and differential diagnosis of GHP. It is hoped that this review will improve clinicians' knowledge of GHP and aid in accurate preoperative diagnosis, thereby reducing the misdiagnosis rate.

Heterotopic pancreas adenocarcinoma in the stomach: A case report and literature review

BACKGROUND

Heterotopic pancreas is a common lesion found in the gastrointestinal tract and is usually considered a benign disease. Reports of malignant change of heterotopic pancreas are scarce.

CASE SUMMARY

A 44-year-old Chinese female underwent a gastroscopy to assess abdominal distension that had persisted for 2 months. A protruding lesion in the gastric antrum was revealed but no malignant tissue was found in the biopsy specimen. The patient's symptom persisted and progressed to repeated vomiting. Endoscopy after 4 months revealed obstruction of the gastric outlet caused by the protruding lesion. A distal gastrectomy was performed. Histopathological examination of the surgical specimen showed the malignant transformation of aberrant pancreas in the stomach. Chemotherapy consisting of folinic acid, fluorouracil, and oxaliplatin was administered for three cycles, and was changed to gemcitabine monotherapy because of adverse effects and increased serum tumor marker levels. The patient remained asymptomatic during a 12-month follow-up.

CONCLUSION

Pancreatic heterotopy should be considered as source of a potentially malignant lesion, and early treatment or close monitoring for aberrant pancreas is recommended.

Pancreatitis in the developmentally anomalous pancreas

Developmental anomalies of the pancreas include more common entities such as pancreas divisum and annular pancreas, and unusual entities such as heterotopic pancreas. While these anomalies can present a diagnostic challenge to the radiologist, when the pancreatic tissue involved in these processes develops pancreatitis, the radiographic appearance can present a diagnostic dilemma. Awareness of these pancreatic anomalies and familiarity with their appearance when inflamed is necessary to distinguish pancreatitis in the developmentally anomalous pancreas from other inflammatory or neoplastic processes.

Ectopic pancreas in the ileum: An unusual condition and our experience

BACKGROUND

Ectopic pancreas in the ileum, including lesions within Meckel diverticulum, can cause severe manifestations and complications; yet, it was seldom reported in English literature.

AIM

This study aimed to raise awareness and provide information for better clinical management of this rare yet serious condition.

METHODS

A total of 1713 cases of small bowel resection were performed in our hospital between 2009 and 2018, among which 10 cases of ileac ectopic pancreas were identified. A comprehensive retrospective review of the 10 cases was taken.

RESULTS

Five lesions were located in the ileum wall and 5 were within Meckel diverticulum. Two lesions within Meckel diverticulum were incidental; the remaining 8 lesions were all associated with abdominal pain, gastrointestinal bleeding, and anemia. Of the 5 patients with lesions in the ileum wall, computed tomography uniformly revealed ileoileal intussusceptions with masses as lead points. Capsule endoscopies were performed in 6 cases, of which 3 showed positive findings. Double-balloon enteroscopy was conducted in one case and revealed an ileal diverticulum. Therapeutically, the offending bowel segments were removed, and intussusceptions were restored except for one case in which diverticulectomy was applied. No relapse or sequela was observed in the follow-up.

CONCLUSIONS

Ileac ectopic pancreas can be seen in the ileum wall or Meckel diverticulum. The majority of the lesions found in clinical practice present with abdominal pain, gastrointestinal bleeding, and anemia. Lesions in the ileum wall often cause ileoileal intussusception. Computed tomography, capsule endoscopy, and double-balloon enteroscopy are helpful preoperative examinations. Segmental small bowel resection is the treatment of choice.

Heterotopic chondroid tissue of the main bile duct mimicking Klatskin tumor: case report and review of the literature

Heterotopic tissue in the bile duct is a very rare condition. There are a few case reports of heterotopic tissue including gastric and pancreatic cells. However, we could not find any data regarding heterotopic chondroid tissue obstructing the common bile duct in the literature. A 56-year-old woman was admitted to our hospital with complaints of progressive jaundice and pruritus. Laboratory test results were within the normal limits except bilirubin and alkaline phosphatase which were 10.8 mg/dL and 256 IU/L, respectively. Endoscopic retrograde cholangiography (ERCP) and computed tomography (CT) revealed a biliary stricture confined to the upper part of the common bile duct. The patient was operated as soon as the bilirubin level dropped below 5 mg/dL by percutaneous transhepatic cholangiography. Despite the lack of a precise confirmation, the patient was prepared for operation considering the possibility of a malignant biliary tumor since the radiographic mass findings together with hyperbilirubinemia were highly suggestive of malignancy. The patient underwent total extrahepatic bile duct resection and Roux-en-Y hepaticojejunostomy, and was discharged without any postoperative complications. Histologic examination of the bile duct and the nodule revealed the presence of a well-demarcated chondroid tissue within the subepithelial connective tissue. Herein, we presented the first case, to our knowledge, of heterotopic chondroid tissue of the common bile duct in the literature. It is a benign condition that should be considered in the differential diagnosis of stricture and mass-forming lesions of the bile duct.

Benign Tumors and Tumorlike Lesions of the Pancreas

The pancreas is a complex organ that may give rise to large number of neoplasms and non-neoplastic lesions. This article focuses on benign neoplasms, such as serous neoplasms, and tumorlike (pseudotumoral) lesions that may be mistaken for neoplasm not only by clinicians and radiologists, but also by pathologists. The family of pancreatic pseudotumors, by a loosely defined conception of that term, includes a variety of lesions including heterotopia, hamartoma, and lipomatous pseudohypertrophy. Autoimmune pancreatitis and paraduodenal ("groove") pancreatitis may also lead to pseudotumor formation. Knowledge of these entities will help in making an accurate diagnosis.

Heterotopic Pancreas: Histopathologic Features, Imaging Findings, and Complications

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.

Heterotopic pancreatic rests: imaging features, complications, and unifying concepts

OBJECTIVE

The spectrum of pancreatic heterotopia will be reviewed, including clinical features, potential complications, and imaging manifestations. This will also include a review of various entities associated with pancreatic heterotopia such as groove pancreatitis and cystic dystrophy of gastroduodenal heterotopic pancreas. These entities were previously thought of as distinct histopathologic entities but now appear to represent manifestations of pancreatic heterotopia.

CONCLUSION

Pancreatic heterotopia and heterotopic pancreatitis can have a wide range of appearances. Several entities, which were previously thought to be distinct, can be considered manifestations of pancreatic heterotopia and heterotopic pancreatitis.