Pancreatic heterotopia and other uncommon causes of non-malignant biliary obstruction

Ectopic pancreas at the ampulla of Vater diagnosed with endoscopic snare papillectomy: A case report and review of literature

BACKGROUND

Ectopic pancreas is a rare developmental anomaly that results in a variety of clinical presentations. Patients with ectopic pancreas are mostly asymptomatic, and if symptomatic, symptoms are usually nonspecific and determined by the location of the lesion and the various complications arising from it. Ectopic pancreas at the ampulla of Vater (EPAV) is rare and typically diagnosed after highly morbid surgical procedures such as pancreaticoduodenectomy or ampullectomy. To our knowledge, we report the first case of confirmed EPAV with a minimally invasive intervention.

CASE SUMMARY

A 71-year-old male with coronary artery disease, presented to us with new-onset dyspepsia with imaging studies revealing a ‘double duct sign’ secondary to a small subepithelial ampullary lesion. His hematological and biochemical investigations were normal. His age, comorbidity, poor diagnostic accuracy of endoscopy, biopsies and imaging techniques for subepithelial ampullary lesions, and suspicion of malignancy made us acquire histological diagnosis before morbid surgical intervention. We performed balloon-catheter-assisted endoscopic snare papillectomy which aided us to achieve en bloc resection of the ampulla for histopathological diagnosis and staging. The patient’s post-procedure recovery was uneventful. The en bloc resected specimen revealed ectopic pancreatic tissue in the ampullary region. Thus, the benign histopathology avoided morbid surgical intervention in our patient. At 15 mo follow-up, the patient is asymptomatic.

CONCLUSION

EPAV is rare and remains challenging to diagnose. This rare entity should be included in the differential diagnosis of subepithelial ampullary lesions. Endoscopic en bloc resection of the papilla may play a vital role as a diagnostic and therapeutic option for preoperative histological diagnosis and staging to avoid morbid surgical procedures.

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.

Heterotopic pancreas: a clinicopathological study of 184 cases from a single high-volume medical center in China

Heterotopic pancreas (HP) is often an incidental finding during operative or endoscopic procedures and described in case reports and small series in the literature. Large clinicopathological studies with a systematic analysis remain lacking. Herein, we identified 184 (0.18%; 184/99 544) consecutive histology-proven HP cases of 89 770 surgical resections and 9774 upper endoscopic biopsies carried out at a single medical center in China. Each case was diagnosed by unequivocal identification of pancreatic acini at a location outside the pancreas. The patients' median age was 49 years (range, 14-82) with a slight female predominance (male/female ratio, 0.94). Clinical presentation at diagnosis was nonspecific. Preoperatively, most (54.9%; 101/184) HP lesions were misdiagnosed. Only 26 HP lesions (14.1%) were correctly diagnosed, all in the stomach except for 1 in the duodenum; 57 (31%) were detected during operative procedures for other conditions. The most frequent location of HP was, in descending order, the stomach (97; 52.7%), small intestine (48; 26%), lesser and greater curvature omentum (18; 10%), spleen and hilar region (5; 2.7%), porta hepatis (2; 1%), gallbladder (1; 0.5%), peridistal esophageal tissue (4; 2.2%), and mesentery (7; 3.8%). The size of HP varied from smaller than 0.5 cm (35.3%), 0.6 to 1 cm (34.8%), to larger than 1.1 cm (29.9%). Because of difficulty in preoperative diagnosis, careful workup for upper gastrointestinal diseases with HP as a differential diagnosis may increase the chance of accurate diagnosis and appropriate patient management.