Developmental biology of the pancreas

Pancreatic morphological abnormality that was challenging to differentiate from an ectopic pancreas: a case report

Background

Protrusion of the lateral contour of the pancreatic head is a pancreatic morphological abnormality, which is known as rare shape atypia. We present a rare case of protrusion of the lateral contour of the pancreatic head, which was challenging to distinguish from an ectopic pancreas.

Case presentation

The patient was a 40-year-old man with a history of acute pancreatitis that occurred twice in the past. He complained of epigastric pain since the day before the visit; his blood workup showed high serum amylase level and a CT scan revealed a 25-mm-large mass with contrast effect from the anterior wall of the gastric pylorus to the duodenum and increased surrounding fatty tissue density. Endoscopic ultrasonography revealed a mass lesion in the gastric pylorus with continuity with the gastric wall and suspected partial continuity with the pancreatic head. Thus, the possibility of pancreatic morphological abnormality or an ectopic pancreas was considered. Following which, resection was attempted and intraoperative findings showed a wide extension of the pancreatic parenchyma from the pancreatic head to the anterior wall of the gastric pylorus to the duodenal bulb. Since the patient only had mild pancreatitis, the resection was judged to be too invasive and was completed by exploratory laparoscopy.

Conclusions

Even if the findings on preoperative CT are suspicious for an ectopic pancreas or tumor, a pancreatic morphological abnormality, such as a protrusion of the lateral contour of the pancreatic head, should be included in the differential diagnosis.

Notch Signaling in Pancreatic Development

The Notch signaling pathway plays a significant role in embryonic cell fate determination and adult tissue homeostasis. Various studies have demonstrated the deep involvement of Notch signaling in the development of the pancreas and the lateral inhibition of Notch signaling in pancreatic progenitor differentiation and maintenance. The targeted inactivation of the Notch pathway components promotes premature differentiation of the endocrine pancreas. However, there is still the contrary opinion that Notch signaling specifies the endocrine lineage. Here, we review the current knowledge of the Notch signaling pathway in pancreatic development and its crosstalk with the Wingless and INT-1 (Wnt) and fibroblast growth factor (FGF) pathways.