Pancreatic neuroendocrine neoplasms coexisting with biliary intraductal papillary mucinous neoplasm: A case report and review of literature

Abstract

Background: Pancreatic neuroendocrine neoplasms (pNENs) are rare, heterogeneous tumors accounting for 1%-2% of pancreatic tumors, with significant malignant potential. Intraductal papillary mucinous neoplasm of the bile duct (IPMN-B) is a rare precancerous lesion in the bile duct system, with potential for malignancy. The combination of pNENs and IPMN-B is exceptionally rare and often leads to misdiagnosis. This study aims to report a rare case of pNENs combined with IPMN-B treated at Yanbian University Hospital to improve understanding and management of this unusual tumor combination.

Case summary: We retrospectively analyzed a case from Yanbian University Hospital. We reviewed clinical records, imaging findings, endoscopic retrograde cholangiopancreatography, surgical exploration, and histopathological examination. The patient was diagnosed with pNENs and IPMN-B. Surgical treatment was performed, with follow-up showing effective management and no significant recurrence.

Conclusion: This case represents the first report of pNENs combined with IPMN-B. It highlights the need for thorough diagnostic evaluation to prevent misdiagnosis and improve treatment strategies.

Keywords: Case report; Endoscopic retrograde cholangiopancreatography; Histopathology; Intraductal papillary mucinous neoplasm of the bile duct; Malignant potential; Pancreatic neuroendocrine neoplasms.

Figure 1

Upper abdominal enhanced computed tomography images. A: The pancreatic head in the arterial phase of upper abdominal enhanced computed tomography (CT); B: The pancreatic head in the venous phase of upper abdominal enhanced CT; C: The pancreatic duct in the upper segment in the arterial phase of upper abdominal enhanced CT; D: The pancreatic duct in the upper segment in the venous phase of upper abdominal enhanced CT. The imaging examinations were performed using a 64-row multidetector CT scanner with scan parameters of 120 kV, 200 mA, slice thickness of 5 mm, and an interval of 5 mm. The patient received an intravenous contrast agent (iodinated contrast agent, 1.5 mL/kg), and the scan duration was 25 seconds for the arterial phase and 70 seconds for the venous phase. The imaging data were independently analyzed by two radiologists with extensive clinical experience, and the conclusions were reached through a consensus assessment.

Figure 2

Imaging and pathological results of the affected area. A and B: Magnetic resonance cholangiopancreatography images of the mass in the pancreatic head region; C: Macroscopic specimen after pathological processing. The imaging examinations were performed using a 3.0 T magnetic resonance imaging scanner for magnetic resonance cholangiopancreatography scanning, and the pathological specimens underwent standard processing procedures, including fixation, dehydration, transparency, embedding, sectioning, and hematoxylin and eosin staining. The imaging data were analyzed by two radiology experts, and the pathological specimens were evaluated macroscopically and microscopically by pathology specialists.

Figure 3

Pathological sections of the specimen. A: Pathological specimen showing pancreatic neuroendocrine carcinomas (small cell neuroendocrine carcinomas) on the left and intraductal papillary mucinous neoplasm of the bile duct on the right [Hematoxylin and eosin (HE) staining, 100 ×]; B: Immunohistochemical image of the pancreatic specimen showing positive neuroendocrine markers (synaptophysin, 100 ×); C: Pathological section of the bile duct specimen showing intraductal papillary mucinous neoplasm (HE staining, 100 ×); D: Immunohistochemical image of the bile duct specimen (Ki-67, 100 ×). The pathological sections underwent standard procedures of fixation, dehydration, embedding, sectioning, and HE staining. All sections were independently reviewed by two pathology specialists, and the conclusions were reached through a consensus assessment.

Figure 4

Clinical and pathological characteristics of pancreatic neuroendocrine carcinomas combined with intraductal papillary mucinous neoplasm of the bile duct.