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

Abstract

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.

Keywords: Cancer risk; Cystic tumors of the pancreas; ITPN; Intraductal tubular papillary neoplasm; Pancreas.

Fig. 1

Preoperative computed tomography (CT). Inhomogeneous hypodense ill-defined focal lesion of the head of the pancreas (white arrows) with a dilated intra- and extrahepatic bile duct system due to a mass effect (black arrows) (A transverse image, porto-venous phase; B coronal image, porto-venous phase). Note the healthy adjacent parenchyma of the pancreas (white asterisks) and lack of signs of local irresectability.

Fig. 2

Percutaneous transhepatic cholangiodrainage (PTCD). Conventional percutaneous cholangiogram with opacification of a dilated intra- and extrahepatic bile duct system (black arrow) with signs of a malignant stenosis at the level of the head of the pancreas (white arrows) (A). Control cholangiogram after positioning of a 8 F PTCD for combined external/internal drainage (black arrow: configuration of the pigtail of the PTCD in the duodenum; white arrows: bridging of the malignant obstruction via the 8 F PTCD) (B).

Fig. 3

Computed tomography following PTCD. Control CT with adequate positioning of the PTCD (black asterisks) and relief of the bile duct system, and constant ill-defined tumor in the head of the pancreas (white arrows) (A transverse image, arterial phase; B coronal image, porto-venous phase).

Fig. 4

Histopathology (hematoxylin-eosin staining). (A) Histopathology of the pancreatic head following Whipple´s procedure reveals an intraductal tubulopapillary neoplasm (ITPN) with typical papillary growth and beginning invasion (arrow). In contrast to IPMN no overt mucin production was observed. (Original magnification, x 25). (B) Intraductal tubulopapillary neoplasm (ITPN) with associated invasive ductal adenocarcinoma (arrow). (Original magnification, x 25).

Fig. 5

Hematoxylin-eosin staining and immunohistochemistry with Cytokeratin 7. (A) Hematoxylin-eosin staining in a higher magnification reveals atypical tumors cells with high-grade dysplasia and a high proliferation rate (arrow). (Original magnification, x 100). (B) Immunohistochemical staining of the tumor shows ubiquitously positive results for Cytokeratin 7 (CK7) as marked in brown color indicating a highly malignant behavior of the tumor. (Original magnification, x 25).