Intraductal tubular papillary neoplasm (ITPN), a novel entity of pancreatic epithelial neoplasms and precursor of cancer: A case report and review of the literature.

Background: Intraductal tubular papillary neoplasm (ITPN) displays a very rare subtype of epithelial neoplasms of the pancreas. ITPN is characterized by intraductal tubulopapillary growth and cellular dysplasia. In contrast to intraductal papillary neoplasm (IPMN) no overt epithelial mucin production is observed. To date, little is known about ITPN and particularly about pancreatic cancer arising in this tumor entity.

Case Presentation: A 68-year-old male presented at our hospital with a distal bile duct occlusion suspicious for adenocarcinoma of the pancreatic head. Preoperative staging revealed no signs of distant metastasis. The patient was surgically explored and pylorus preserving duodenopancreatectomy was performed for a solid pancreatic head tumor. Final histopathology surprisingly revealed an ITPN with an associated invasive carcinoma pT3, pN0 (0/12), R0, G2.

Discussion: Patients with ITPN frequently present with jaundice suspicious for a bile duct stenosis or a malignant tumor of the pancreatic head. Although, it is possible to diagnose ITPN by endoscopic retrograde cholangiopancreaticography, many tumors are found not before histopathological examination. Differential diagnosis includes ductal adenocarcinoma of the pancreas, neuroendocrine tumors, IPMN, distal bile duct tumors, and solid pseudopapillary neoplasms. Using immunohistochemistry, other entities of pancreatic tumors can be ruled out. In case of R0 resection oncological prognosis is described to be more favorable when compared to regular ductal adenocarcinoma.

Conclusion: ITPN displays a rare entity of pancreatic neoplasms. As shown in the present case report, there is a relevant potential of malignant transformation and therefore radical surgical resection and oncologic follow-up is warranted.