Intraductal oncocytic papillary carcinoma with invasion arising from the accessory pancreatic duct

Comprehensive characterization of intraductal oncocytic papillary neoplasm (IOPN) of the pancreas: a systematic and critical review

Intraductal oncocytic papillary neoplasm (IOPN) of the pancreas is a recently recognized pancreatic tumor. Here, we aimed to determine the most essential features with the systematic review tool. PubMed, SCOPUS, and Embase were searched for studies reporting data on pancreatic IOPN. The clinicopathological, immunohistochemical, and molecular data were extracted and summarized. Then, a comparative analysis of the molecular alterations of IOPN with those of pancreatic ductal adenocarcinoma and intraductal papillary mucinous neoplasm from reference cohorts (including The Cancer Genome Atlas) was conducted. The key findings from 414 IOPNs were as follows: 1) Clinicopathological Features: Male-to-female ratio was 1,5:1. Pancreatic head was the most common site (131/237, 55.3%), but a diffuse tumor extension involving more than one pancreatic segment was described in about 1/5 of cases (49/237, 20.6%). The mean size was 45.5 mm. An associated invasive carcinoma was present in 50% of cases (168/336). In those cases, most tumors were pT1/pT2 and pN0 (>80%), and vascular invasion was uncommon (20.6%). Regarding survival, more than 90% of patients were alive after surgical resection. 2) Immunohistochemical and Molecular Features: The most expressed mucins were MUC5AC (110/112, 98.2%) and MUC6 (78/84, 92.8%). Compared with pancreatic ductal adenocarcinoma and intraductal papillary mucinous neoplasm, the classic pancreatic drivers KRAS, TP53, CDKN2A, SMAD4, and GNAS were less altered in IOPN (p<0.01). Moreover, fusions involving PRKACA or PRKACB genes were detected in all of 68 cases examined, with PRKACB::ATP1B1 as the most common (27/68 cases, 39.7%). These genomic events emerged as an entity-defining molecular alteration of IOPN (p<0.01). Thus, such fusions represent a promising biomarker for diagnostic purposes. Recent evidence also suggests their role in influencing the acquisition of oncocytic morphology. IOPN is a distinct pancreatic neoplasm with specific clinicopathological and molecular features. Considering the clinical/prognostic implications, its recognition is essential for pathologists and, ultimately, patients' management.

Systematic review of challenging issues in pathology of intraductal papillary mucinous neoplasms

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) are a cystic precursor to pancreatic cancer. IPMNs deemed clinically to be at high-risk for malignant progression are frequently treated with surgical resection, and pathological examination of the pancreatectomy specimen is a key component of the clinical care of IPMN patients.

METHODS

Systematic literature reviews were conducted around eight topics of clinical relevance in the examination of pathological specimens in patients undergoing resection of IPMN.

RESULTS

This review provides updated perspectives on morphological subtyping of IPMNs, classification of intraductal oncocytic papillary neoplasms, nomenclature for high-grade dysplasia, assessment of T stage, distinction of carcinoma associated or concomitant with IPMN, role of molecular assessment of IPMN tissue, role of intraoperative assessment by frozen section, and preoperative evaluation of cyst fluid cytology.

CONCLUSIONS

This analysis provides the foundation for data-driven approaches to several challenging issues in the pathology of IPMNs.

Preoperatively diagnosed intraductal oncocytic papillary neoplasm of the pancreas with prominent invasion: a case report

Previously considered as one of the less-invasive subtypes of intraductal papillary mucinous neoplasm, intraductal oncocytic papillary neoplasm (IOPN) has recently been acknowledged as a new entity of pancreatic tumor. We herein present a case of preoperatively diagnosable IOPN invasion in the stomach and colon. A 78-year-old woman was referred to our hospital for evaluation of anorexia and gastroesophageal reflux. Upper gastrointestinal endoscopy revealed a gastric subepithelial lesion with ulcerated mucosa that required hemostasis. Computed tomography revealed a 96-mm-diameter solid tumor with a well-defined border and centrally positioned necrotic area, extending from the stomach to the transverse colon and pancreatic tail. Because it was suspected to be a pancreatic solid tumor with direct stomach invasion, endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) was performed, which led to a preoperative diagnosis of IOPN. Moreover, laparoscopic pancreatosplenectomy, proximal gastrectomy, and transverse colectomy were performed. Analysis of the surgical specimen revealed that the tumor was IOPN and had invaded the stomach and transverse colon. Lymph node metastasis was also confirmed. These findings indicate that IOPN can manifest as an invasive tumor, and EUS-FNB may be equally helpful for assessing the invaded area of a cystic lesion as it is for a solid lesion.

Intraductal oncocytic papillary carcinoma of the pancreas showing numerous hyaline globules in the lumen

Two cases of intraductal oncocytic papillary carcinoma (IOPC) treated surgically were analyzed on light microscopy and immunohistochemistry: that of a 61-year-old man and that of a 55-year-old man. There were no clinical symptoms in either case. Pancreatic abnormalities were discovered incidentally on CT. Various clinical examinations were carried out, and the preoperative diagnosis was intraductal papillary mucinous carcinoma (IPMC) in both cases. Surgery was performed. Macroscopic observation of tissue cross-sections indicated multilocular cystic mass containing polypoid lesions encapsulated by the dilated pancreatic duct. Histologically, the cyst walls were lined by columnar epithelial cells with complex papillary projections associated with oxyphilic cytoplasm, and they were strongly immunoreactive with anti-mitochondrial antibody in the cytoplasm. Electron microscopy showed numerous mitochondria in the cytoplasm. IOPC was diagnosed. Interestingly, amorphous hyaline globules were produced from the oxyphilic cells, which exhibited a bud-like appearance. The hyaline globules were not positive for mucin staining. No case of IPMC with hyaline globules has been reported to date. The production of hyaline globules may be related to oncocytic differentiation. It is suggested that hyaline globules should be regarded as a characteristic of IOPC.

Intraductal oncocytic papillary neoplasms of the pancreas and bile ducts: a description of five new cases and review based on a systematic survey of the literature

BACKGROUND

Intraductal oncocytic papillary neoplasms (IOPN) are rare tumors of the pancreatic and biliary ductal system. It is not absolutely clear if the molecular and clinicopathologic characteristics of IOPN differ significantly from other related lesions, namely intraductal papillary mucinous neoplasms (IPMN). Therefore it is not clear if it is reasonable to consider IOPN as a separate diagnostic and clinical entity.

METHODS

In order to describe the clinicopathologic characteristics of IOPN and to compare them with the IPMN profile, we performed a systematic review of the literature and additionally studied five previously unreported IOPN cases.

RESULTS

IOPN differ from IPMN by lack of K-ras gene mutations in all studied cases. Several differences in the clinical and biological profile between IOPN and IPMN exist, but they are of quantitative rather than of qualitative nature. Additionally, pancreaticobiliary or gastric-foveolar IPMN components may coexist with IOPN component within a single lesion, which suggests at least a partial relation of the pathogenetic pathways of IPMN and IOPN. Importantly, the pathogenesis of accumulation of mitochondria and oxyphilic appearance of IOPN remains unknown.

CONCLUSIONS

At present, there are no reliable criteria other than histopathological picture and K-ras gene status to differentiate IOPN from IPMN. In particular, no clear differences in optimal treatment options and prognosis between these tumors are known. Further studies are needed to clarify the biology of IOPN and to establish their position in clinicopathologic classifications of pancreatic tumors.

[A case of intraductal papillary mucinous neoplasm arising from Santorini's duct in a patient with complete type of pancreas divisum]

There have been an increasing number of reports of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas since its first report by Ohhasi et al. in 1982. Most IPMNs arise from Wirsungs duct or its branches, whereas IPMNs arising from Santorinis duct are rare. Pancreas divisum is a common congenital anatomical anomaly characterized by the lack of fusion of the ventral and dorsal parts of the pancreas during the eighth week of fetal development. Although clinical significance of pancreas divisum has been the subject of debate for many years, there seems to be little doubt that in certain patients there is a causal relation between pancreas divisum and pancreatitis. Also, it is occasionally accompanied by a pancreatic tumor. Herein, we report a case of IPMN arising from Santorinis duct in patient with complete type of pancreas divisum.

Pancreatic intraductal papillary-mucinous neoplasms: a new and evolving entity

For a long time, intraductal tumors of the pancreas were neglected because they were misdiagnosed as mucinous cystadenocarcinoma, ordinary ductal adenocarcinoma, or chronic pancreatitis. Only in recent years have they been recognized as clinical and pathological entities. Most common are the intraductal papillary-mucinous neoplasms. Although they show an adenoma-carcinoma sequence, they have proved to have a more favorable prognosis than ductal adenocarcinoma, when resected in a preinvasive state. Recently, it has become clear that they constitute a heterogeneous group with at least four subtypes. Their stratification reveals that the various intraductal papillary-mucinous neoplasm subtypes have different biological properties with different prognostic implications.

Intraductal Oncocytic Papillary Neoplasm of the Extrahepatic Biliary Tree: First Report

Tumors with oncocytic differentiation may occur in a variety of organs, but are extremely rare in the biliary system. Intraductal oncocytic papillary neoplasms (IOPNs) were first described in the pancreas to differentiate a rare subset of pancreatic neoplasm from the intraductal papillary mucinous neoplasms (IPMNs). IOPN of the extrahepatic biliary tree has not been previously described. We describe the first case of an intraductal oncocytic papillary neoplasm at the bifurcation of the common hepatic duct in a 52-year-old white male with a two-year history of intermittent biliary obstruction.