Invasive intraductal papillary mucinous tumor of the pancreas with simultaneous invasion of the stomach and duodenum

Intraductal Papillary Mucinous Neoplasm of the Pancreas: A Challenging Diagnosis

Intraductal papillary mucinous neoplasm of the pancreas (IPMN) was classified as a distinct entity from mucinous cystic neoplasm by the WHO in 1995. It represents a mucin-producing tumor that originates from the ductal epithelium and can evolve from slight dysplasia to invasive carcinoma. In addition, different aspects of tumor progression may be seen in the same lesion. Three types are recognized, the branch duct variant, the main duct variant, which shows a much higher prevalence for malignancy, and the mixed-type variant, which combines branch and main duct characteristics. Advances in cross-sectional imaging have led to an increased rate of IPMN detection. The main imaging characteristic of IPMN is the dilatation of the pancreatic duct without the presence of an obstructing lesion. The diagnosis of a branch duct IPMN is based on the proof of its communication with the main pancreatic duct on MRI-MRCP examination. Early identification by imaging of the so-called worrisome features or predictors for malignancy is an important and challenging task. In this review, we will present recent imaging advances in the diagnosis and characterization of different types of IPMNs, as well as imaging tools available for early recognition of worrisome features for malignancy. A critical appraisal of current IPMN management guidelines from both a radiologist's and surgeon's perspective will be made. Special mention is made of complications that might arise during the course of IPMNs as well as concomitant pancreatic neoplasms including pancreatic adenocarcinoma and pancreatic endocrine neoplasms. Finally, recent research on prognostic and predictive biomarkers including radiomics will be discussed.

Successful management of life-threatening bleeding of intraductal papillary mucinous neoplasms in the pancreatic head

Complications associated with intraductal papillary mucinous neoplasms, such as acute pancreatitis, perforation, and fistula formation, have been documented. Intraductal papillary mucinous neoplasm with intratumoral hemorrhage is rare. To the best of our knowledge, there have been no previous reports of intraductal papillary mucinous neoplasm rupture and bleeding with intra-abdominal hemorrhage. A 74-year-old woman complained of acute upper right abdominal pain. She was under follow-up for an intraductal papillary mucinous neoplasm in the pancreatic head. Contrast-enhanced computed tomography revealed intraductal papillary mucinous neoplasm rupture and bleeding with intra-abdominal hemorrhage. The bleeding was treated with selective endovascular embolization of a branch of the gastroduodenal artery. Follow-up examinations are recommended even for intraductal papillary mucinous neoplasm patients without malignant findings because of the potential risk of rupture and bleeding with intra-abdominal hemorrhage. Clinicians should be aware of this possibility to ensure that patients are appropriately treated.

Intraductal papillary mucinous neoplasms of the pancreas complicated with intraductal hemorrhage, perforation, and fistula formation: CT and MR imaging findings with pathologic correlation

OBJECTIVE

To correlate the CT and MR images with pathologic findings on intraductal papillary mucinous neoplasms (IPMNs) complicated with intraductal hemorrhage, perforation, and fistula.

MATERIALS AND METHODS

We retrospectively evaluated the CT (n = 5), MR imaging (n = 4), and pathological features of five IPMN patients complicated with intraductal hemorrhage (n = 5), perforation (n = 1), and fistula into the duodenum and jejunum (n = 1).

RESULTS

Intraductal hemorrhage could be detected as high attenuation on non-contrast CT in two of the five cases, and as high signal intensity on fat-suppressed T1-weighted MR images in all four of the cases. Perforation and fistula could be recognized on CT images. In all IPMNs, denuded epitheliums were observed pathologically. Dissolution of the duct wall and extension of mucinous materials were seen at the area of denuded epithelium. Perforations and fistula, without evidence of cancer invasion, were recognized in the dissolved duct wall. Pathogenesis of the perforations and fistula formations appeared to be related to excessive pressure in the dilated ducts and autodigestion of enzyme-rich fluids.

CONCLUSION

Complications with IPMN could be recognized on CT and fat-suppressed T1-weighted MR images. Intraductal hemorrhage might be predictive sign of perforation and fistula formation.

Intraductal papillary mucinous neoplasms of the pancreas showing fistula formation into other organs

BACKGROUND

This study assessed the mechanism of fistula formation in intraductal papillary mucinous neoplasm (IPMN) of the pancreas.

METHODS

A total of 274 patients with IPMN who had been diagnosed by endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography (EUS) at our center were enrolled. The patients with IPMN which had fistula formation into other organs were investigated retrospectively as to (1) clinical prevalence and the organs penetrated by IPMN, (2) analysis of the mechanism of fistula formation by immunohistopathological study, (3) efficacy of EUS in progression assessment, and (4) prognosis.

RESULTS

Among the subjects, fistula formation into other organs was observed in 18 patients (6.6%) and into 28 organs. There were 7 patients (39%) in whom multiple organs were penetrated. Of 16 patients who had undergone investigation of the expression of mucin markers, 94% had an intestinal-type tumor. Of 9 patients who had undergone surgery or autopsy, 67% showed mechanical penetration without invasion around the fistula. Only papillary protrusions were seen by EUS in 4 of these patients with noninvasive papillary adenocarcinoma showing mechanical penetration. All 5 patients who had pancreatic parenchymal invasion showed a mass with a mixed-echo pattern in addition to papillary protrusions shown by EUS, corresponding to colloid carcinoma.

CONCLUSIONS

There were 2 processes in the development of fistulas in IPMN. Of those patients showing fistula formation, 94% had intestinal-type IPMN, and 67% showed mechanical penetration. Delineation of a mass with the mixed-echo pattern suggested an invasive penetration due to colloid carcinoma.

Pancreatobiliary fistula associated with an intraductal papillary-mucinous pancreatic neoplasm manifesting as obstructive jaundice: report of a case

We report a pancreatobiliary fistula caused by an intraductal papillary-mucinous pancreatic neoplasm (IPMN), manifesting as obstructive jaundice. Computed tomography showed dilatation of the bile duct and main pancreatic duct, with multiple cystic masses in the head of the pancreas. Endoscopic retrograde pancreatocholangiography showed a patulous papilla with mucin secretion. Contrast enhancement outlined amorphous material obstructing the lower part of the common hepatic duct. Pancreatogram and magnetic resonance cholangiopancreatography showed diffuse dilatation of the main pancreatic duct and side branches without communication with the adjacent organs or duct. We performed pancreaticoduodenectomy for IPMN of the pancreatic head and a tumor-like lesion in the lower common bile duct (CBD). Macroscopically, impacted thick mucus protruded into the CBD from the pancreas via a pancreatobiliary fistula. Histologic examination revealed a pancreatobiliary fistula caused by intraductal papillary-mucinous carcinoma of the pancreas with mucin hypersecretion, an adenoma without interstitial infiltration, and isolated implantation of an IPMN in the bile duct mucosa around the fistula.

Intraductal papillary mucinous carcinoma with atypical manifestations: Report of two cases

Intraductal papillary mucinous neoplasms (IPMNs) are a well-characterized group of mucin-producing cystic neoplasms of the clear malignant potential type. We report here two cases of intraductal papillary mucinous carcinoma (IPMC) with atypical manifestations. In one case, we discussed a pseudomyxoma peritonei caused by a ruptured IPMC. In the other case we discussed the fistulization of IPMC into the stomach and duodenum. These two cases suggest that IPMN can either spontaneously rupture causing mucinous materials to spill into the free abdominal cavity or directly invade adjacent organs resulting in fistula development.

Endoscopic ultrasound-guided fine-needle aspiration cytology diagnosis of intraductal papillary mucinous neoplasm of the pancreas is highly predictive of pancreatic neoplasia

Intraductal papillary mucinous neoplasms (IPMN) have been considered difficult to diagnose by fine-needle aspiration (FNA) cytology. We identified 57 cases diagnosed as IPMN or consistent with IPMN by endoscopic ultrasound (EUS)-guided FNA over a 9-yr period. Histologic follow-up was available for 20 patients (35%). Pancreatic neoplasia was demonstrated in 18 of these cases (90%). The histologic diagnoses were IPMN (16 cases), pancreatic intraductal neoplasia (grade 1b, 1 case), invasive mucin-producing adenocarcinoma (1 case), and chronic pancreatitis with a pseudocyst (2 cases). Sixty-two cases of IPMN without coexisting adenocarcinoma were diagnosed by histology during this time period. Of these, 35 (56%) had a preceding EUS-guided FNA. The diagnosis made by EUS-guided FNA in these 35 cases was negative or nondiagnostic (6 cases), benign cyst (1 case), chronic pancreatitis (2 cases), atypical ductal cells (2 cases), adenocarcinoma or suspicious for adenocarcinoma (3 cases), consistent with mucinous cystic neoplasm (4 cases), and IPMN or consistent with IPMN (16 cases). An EUS FNA diagnosis of probable or definite neoplasia was, therefore, made in 71% of cases of histologically proven IPMN.