Intraductal tubulopapillary neoplasm (ITPN) of the pancreas associated with an invasive component: a case report with review of the literature

Abstract

Background: Intraductal tubulopapillary neoplasm (ITPN) depicts a distinct entity in the subgroup of premalignant epithelial tumors of the pancreas. Although the histomorphological and immunophenotypical characterization of ITPN has been described by several authors in terms of report of case series in the past, the rarity of that tumor subtype and similarity to other entities still makes identification of ITPN a challenge for radiologists and pathologists. To date, little is known about tubulopapillary carcinoma that can evolve from ITPN.

Case presentation: In the present work, we analyze one case of ITPN associated with an invasive component and discuss the results involving the current literature. Collected patient data included medical history, clinical symptoms, laboratory tests, radiological imaging, reports of interventions and operation, and histopathological and immunohistochemical examinations. The patient initially presented with acute pancreatitis. A solid tumor obstructing the main pancreatic duct and sticking out of the papilla of Vater was detected and caught via endoscopic intervention. Histopathological examination of the specimen revealed mainly tubular growth pattern with back to back tubular glands. Immunohistochemically, the tumor was strongly positive for keratin 7 (CK7) and pankeratin AE1/AE3, and alpha 1 antichymotrypsin; negative for synaptophysin and chromogranin A, CDx2, CK20, S100, carcinoembryonic antigen (CEA), MUC 2, MUC5AC, and somatostatin; and in part positive for CA19-9. Extended pancreatoduodenectomy was performed, the final diagnosis was tubulopapillary carcinoma grown in an ITPN.

Conclusion: The identification of an ITPN of the pancreas can be a challenging task. Endoscopic retrograde cholangiopancreaticography is an excellent tool to directly see and indirectly visualize the intraductal solid tumor and to take a biopsy for histopathological evaluation at the same time. Together with a thorough immunohistochemical workup, differential diagnoses can be ruled out quickly. To date, reports of ITPN are rare and little is known about the potential for malignant transformation and the prognosis of tubulopapillary carcinoma grown from an ITPN. Radical surgical resection following oncologic criteria is recommended; however, more data will be needed to assess an adequate treatment and follow-up standard.

Keywords: Carcinoma; Intraductal; Neoplasia; Pancreas; Pancreaticoduodenectomy.

Fig. 1

CT of the abdomen (portalvenous phase) at the initial presentation shows a dilated pancreatic duct without evidence of an obstructive process or cholelithiasis

Fig. 2

Transgastric endosonography reveals a dilation of the pancreatic duct to a diameter of approximately 7 mm

Fig. 3

A snapshot on ERCP shows a thrombus-like formation sticking out of the papilla of Vater

Fig. 4

After slight manipulation at the papilla, a tumor nodule drops out of the duct and can be collected via endoscopy

Fig. 5

After the specimen has been removed, intubation of the papilla can be performed for pancreatography

Fig. 6

A 7-French plastic stent is placed into the congested distal pancreatic duct in order to drain the dilated duct of the pancreatic body and tail

Fig. 7

Contrast-enhanced CT in portal venous phase shows the hypodense lesion in the pancreatic head

Fig. 8

This histological slide depicts an intraductal growing area of the tumor in the main pancreatic duct, which was initially observed at endoscopy. A large percentage of the duct’s circumference is lined by normal appearing epithelial cells. Hematoxylin and eosin, ×100

Fig. 9

A higher magnification of the intraductal tumor with back to back glands. Hematoxylin and eosin, ×300

Fig. 10

In this area, the neoplasia was characterized by a nodular tumor growth. Although the appearance is suggestive of invasive disease, intraductal growth only cannot be ruled out. Hematoxylin and eosin, ×200

Fig. 11

Keratin 7-positive tumor cells are labeled with a brown coloration. In the center of the slide, there are single tumor cells indicating invasive disease. Anti-CK7, DAB