Role of frozen section assessment for intraductal papillary and mucinous tumor of the pancreas

Pancreatoscopy-Guided Endotherapies for Pancreatic Diseases

Per-oral pancreatoscopy (POP) is a pancreas-preserving modality that allows for targeted pancreatic duct interventions, particularly in cases where standard techniques fail. POP specifically has an emerging role in the diagnosis, risk stratification, and disease extent determination of main duct intraductal papillary mucinous neoplasms (IPMNs). It has also been successfully used for laser ablation of IPMNs in poor surgical candidates, lithotripsy for complex stone disease, and laser stricturoplasty. As experience with POP increases beyond select referral center practices, further studies validating POP efficacy with long-term follow-up will help clarify when POP-guided intervention is most beneficial in relation to surgical intervention.

Novel Insights into Postoperative Surveillance in Resected Pancreatic Cystic Neoplasms-A Review

Pancreatic cystic lesions (PCL) are frequently encountered in clinical practice and some are referred to surgery due to their neoplastic risk or malignant transformation. The management of PCL involves complex decision-making, with postoperative surveillance being a key component for long-term outcomes, due to the potential for recurrence and postoperative morbidity. Unfortunately, the follow-up of resected patients is far from being optimal and there is a lack of consensus on recommendations with regard to timing and methods of surveillance. Here, we summarize the current knowledge on the postoperative surveillance of neoplastic pancreatic cysts, focusing on the mechanisms and risk factors for recurrence, the recurrence rates according to the initial indication for surgery, the final result of the surgical specimen and neoplastic risk in the remaining pancreas, as well as the postsurgical morbidity comprising pancreatic exocrine insufficiency, metabolic dysfunction and diabetes after resection, according to the type of surgery performed. We analyze postsurgical recurrence rates and morbidity profiles, as influenced by different surgical techniques, to better delineate at-risk patients, and highlight the need for tailored surveillance strategies adapted to preoperative and operative factors with an impact on outcomes.

Intraoperative pancreatoscopy in pancreaticoduodenectomy for intraductal papillary mucinous neoplasms of the pancreas: Application to the laparoscopic approach

BACKGROUND

/Purpose: Owing to the characteristics of IPMNs, which have variable skipped lesions along the main pancreatic duct (MPD), determining the surgical margins is very difficult. This study aimed to investigate the efficacy and potential oncologic impact of intraoperative pancreatoscopy (IOP) compared to frozen section biopsy (FSB) in pancreaticoduodenectomy (PD) for pancreatic head IPMNs.

METHODS

Data of patients who underwent PD for IPMNs of the pancreas between October 2007 and May 2020 were retrospectively reviewed. IOP was performed in selected patients with IPMNs with inconclusive MPD involvement based on preoperative evaluations. Patients were divided into two groups, IOP group, FSB group. Clinicopathologic features and oncologic outcomes were compared between two groups.

RESULTS

60 patients underwent PD (laparoscopic or robotic, 42; open, 18) for pancreatic head IPMNs. IOP was safely performed in 28 patients, including minimally invasive approach used in 21 patients (35%). IOP group had a significantly larger MPD size (9.15 ± 4.79 mm vs 6.43 ± 4.11 mm, p = 0.021). Based on IOP, the initial surgical plan could be changed in 5 patients (17.8%) for complete resection. Recurrence occurred in 2 patients in FSB group and 3 patients in IOP group during the follow-up period (33.2 months, [range, 3.5-131.4 months]). Overall disease-free survival rate did not significantly differ between two groups (p = 0.529).

CONCLUSIONS

IOP can be safely performed in patients with pancreatic head IPMNs with MPD dilatation, even in the laparoscopic approach. Further studies evaluating the long-term oncologic effect of IOP for the management of IPMNs are required.

The role of pancreatoscopy in the diagnostic work-up of intraductal papillary mucinous neoplasms: a systematic review and meta-analysis

BACKGROUND

Confirming the diagnosis, invasiveness, and disease extent of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas is challenging. The aim of this study was to summarize the literature on the efficacy and safety of peroral pancreatoscopy (POP) in the diagnosis of IPMN, including the impact of pre- and intraoperative POP on the management of IPMN.

METHODS

The EMBASE, Medline Ovid, Web of Science, Cochrane CENTRAL, and Google Scholar databases were systematically searched for articles. Eligible articles investigated cohorts of patients who underwent POP for (suspected) IPMN.

RESULTS

25 articles were identified and included in this review; with 22 of these reporting on the diagnostic yield of POP in IPMN and 11 reporting on the effect of pre- or intraoperative POP on clinical decision-making. Cannulation and observation rates, and overall diagnostic accuracy were high across all studies. Frequently reported visual characteristics of IPMN were intraductal fish-egg-like lesions, hypervascularity, and granular mucosa. Overall, the adverse event rate was 12 %, primarily consisting of post-endoscopic retrograde cholangiopancreatography pancreatitis, with a pooled rate of 10 %, mostly of mild severity. Regarding the impact of POP on clinical decision-making, POP findings altered the surgical approach in 13 %-62 % of patients.

CONCLUSION

POP is technically successful in the vast majority of patients with (suspected) IPMN, has a consistently high diagnostic accuracy, but an adverse event rate of 12 %. Data on intraoperative pancreatoscopy are scarce, but small studies suggest its use can alter surgical management. Future studies are needed to better define the role of POP in the diagnostic work-up of IPMN.

Pylorus-Preserving Total Pancreatectomy for Intraductal Papillary Mucinous Neoplasm in the Setting of Previous Roux-en-Y Cystjejunostomy for Pancreatic Pseudocyst

Background: Intraductal papillary mucinous neoplasms (IPMNs) are cystic lesions of the pancreas with malignant potential. The Sendai and Fukuoka criteria offer guidelines for surgical management of an IPMN.

Presentation: A 69-year-old patient with a history of recurrent pancreatitis presented with steatorrhea and unintentional weight loss. Upon workup, he was found to have an IPMN, for which he met Sendai and Fukuoka criteria for surgical management. At the time of surgery, the patient's reported operative history was remarkable only for cholecystectomy; however, during the procedure, he was found to have a Roux-en-Y limb of jejunum attached to the head of the pancreas. Postoperative discussion with the patient and family revealed that this was likely the result of a past cystjejunostomy procedure used to drain what may have been a pancreatic pseudocyst that had developed after a bout of severe acute pancreatitis. Ultimately, the previously created Roux-en-Y limb was used in the reconstruction after specimen excision by total pancreatectomy.

Conclusions: Main duct IPMNs have a high incidence of carcinoma. Those that meet Sendai and Fukuoka criteria should be surgically managed. In this study we present a case of IPMN management by total pancreatectomy with unique reconstruction using a previously created Roux-en-Y limb.

Role of pancreatoscopy in management of pancreatic disease: A systematic review

BACKGROUND

Per-oral pancreatoscopy (POP) plays a role in the diagnosis and therapy of pancreatic diseases. With recent technological advances, there has been renewed interest in this modality.

AIM

To evaluate the efficacy and safety of POP in management of pancreatic stone disease and pancreatic ductal neoplasia.

METHODS

To determine the safety and efficacy of POP in the management of pancreatic diseases, a systematic search was conducted in MEDLINE, EMBASE and Ovid. Articles in languages other than English and case reports were excluded. All published case series were eligible. Data specific to POP were extracted from studies, which combined cholangiopancreatoscopy. Ten studies were included in the analysis of POP therapy for pancreatic stone disease, and 15 case series satisfied the criteria for inclusion for the role of POP in the management of pancreatic ductal neoplasia. The examined data were subcategorized according to adjunctive modalities, such as direct tissue sampling, cytology, the role of intraoperative POP, intraductal ultrasound (IDUS) and POP combined with image-enhancing technology.

RESULTS

The success rate for complete ductal stone clearance ranged from 37.5%-100%. Factors associated with failure included the presence of strictures, multiple stones and the inability to visualize the target area. Although direct visualization can identify malignant and premalignant conditions, there is significant overlap with benign diseases. Visually-directed biopsies provide a high degree of accuracy, and represent a unique approach for tissue acquisition in patients with ductal abnormalities. Addition of pancreatic fluid cytology increases diagnostic yield for indeterminate lesions. Protrusions larger than 3 mm noted on IDUS are significantly more likely to be associated with malignancy. The rate of adverse events associated with POP ranged from 0%-35%.

CONCLUSION

Current evidence supports wider adoption of pancreatoscopy, as it is safe and effective. Improved patient selection and utilization of novel technologies may further enhance its role in managing pancreatic disease.

The Clinical Management of Main Duct Intraductal Papillary Mucinous Neoplasm of the Pancreas

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas comprise a heterogeneous group of intraductal mucin-producing neoplasms representing a typical adenoma-to-carcinoma sequence. The involvement of the main pancreatic duct (MPD) is a feature of paramount importance, directly related to a more aggressive biology and a higher malignancy rate.

METHOD

We review and discuss the clinical management of IPMNs with a MPD involvement, recalling the different consensus guidelines and addressing recent controversies in literature, presenting the current clinical practice in Verona Pancreas Institute.

RESULTS

All the aspects of surgical management were discussed, from the indication for surgery to the intraoperative management and the follow-up strategies.

CONCLUSION

The management of presumed IPMNs involving the MPD at our Institution is in line with the International Association of Pancreatology 2012 guidelines, revised in 2016. Surgical resection proposed should achieve the complete removal of the tumor with negative margins. Despite a good prognosis in terms of survival of overall resected main duct intraductal papillary mucinous neoplasms, follow-up should not be discontinued.

The Impact of New Technologic and Molecular Advances in the Daily Practice of Gastrointestinal and Hepatobiliary Pathology

The practice of anatomic pathology, and of gastrointestinal pathology in particular, has been dramatically transformed in the past decade. In addition to the multitude of diseases, syndromes, and clinical entities encountered in daily clinical practice, the increasing integration of new technologic and molecular advances into the field of gastroenterology is occurring at a fast pace. Application of these advances has challenged pathologists to correlate newer methodologies with existing morphologic criteria, which in many instances still provide the gold standard for diagnosis. This review describes the impact of new technologic and molecular advances on the daily practice of gastrointestinal and hepatobiliary pathology. We discuss new drugs that can affect the gastrointestinal tract and liver, new endoluminal techniques, new molecular tests that are often performed reflexively, new imaging techniques for evaluating hepatocellular carcinoma, and modified approaches to the gross and histologic assessment of tissues that have been exposed to neoadjuvant therapies.

Pathologic Evaluation and Reporting of Intraductal Papillary Mucinous Neoplasms of the Pancreas and Other Tumoral Intraepithelial Neoplasms of Pancreatobiliary Tract: Recommendations of Verona Consensus Meeting

BACKGROUND

There are no established guidelines for pathologic diagnosis/reporting of intraductal papillary mucinous neoplasms (IPMNs).

DESIGN

An international multidisciplinary group, brought together by the Verona Pancreas Group in Italy-2013, was tasked to devise recommendations.

RESULTS

(1) Crucial to rule out invasive carcinoma with extensive (if not complete) sampling. (2) Invasive component is to be documented in a full synoptic report including its size, type, grade, and stage. (3) The term "minimally invasive" should be avoided; instead, invasion size with stage and substaging of T1 (1a, b, c; ≤ 0.5, > 0.5-≤ 1, > 1 cm) is to be documented. (4) Largest diameter of the invasion, not the distance from the nearest duct, is to be used. (5) A category of "indeterminate/(suspicious) for invasion" is acceptable for rare cases. (6) The term "malignant" IPMN should be avoided. (7) The highest grade of dysplasia in the non-invasive component is to be documented separately. (8) Lesion size is to be correlated with imaging findings in cysts with rupture. (9) The main duct diameter and, if possible, its involvement are to be documented; however, it is not required to provide main versus branch duct classification in the resected tumor. (10) Subtyping as gastric/intestinal/pancreatobiliary/oncocytic/mixed is of value. (11) Frozen section is to be performed highly selectively, with appreciation of its shortcomings. (12) These principles also apply to other similar tumoral intraepithelial neoplasms (mucinous cystic neoplasms, intra-ampullary, and intra-biliary/cholecystic).

CONCLUSIONS

These recommendations will ensure proper communication of salient tumor characteristics to the management teams, accurate comparison of data between analyses, and development of more effective management algorithms.

Pathological features and diagnosis of intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a noninvasive epithelial neoplasm of mucin-producing cells arising in the main duct (MD) and/or branch ducts (BD) of the pancreas. Involved ducts are dilated and filled with neoplastic papillae and mucus in variable intensity. IPMN lacks ovarian-type stroma, unlike mucinous cystic neoplasm, and is defined as a grossly visible entity (≥ 5 mm), unlike pancreatic intraepithelial neoplasm. With the use of high-resolution imaging techniques, very small IPMNs are increasingly being identified. Most IPMNs are solitary and located in the pancreatic head, although 20%-40% are multifocal. Macroscopic classification in MD type, BD type and mixed or combined type reflects biological differences with important prognostic and preoperative clinical management implications. Based on cytoarchitectural atypia, IPMN is classified into low-grade, intermediate-grade and high-grade dysplasia. Based on histological features and mucin (MUC) immunophenotype, IPMNs are classified into gastric, intestinal, pancreatobiliary and oncocytic types. These different phenotypes can be observed together, with the IPMN classified according to the predominant type. Two pathways have been suggested: gastric phenotype corresponds to less aggressive uncommitted cells (MUC1 -, MUC2 -, MUC5AC +, MUC6 +) with the capacity to evolve to intestinal phenotype (intestinal pathway) (MUC1 -, MUC2 +, MUC5AC +, MUC6 - or weak +) or pancreatobiliary /oncocytic phenotypes (pyloropancreatic pathway) (MUC1 +, MUC 2-, MUC5AC +, MUC 6 +) becoming more aggressive. Prognosis of IPMN is excellent but critically worsens when invasive carcinoma arises (about 40% of IPMNs), except in some cases of minimal invasion. The clinical challenge is to establish which IPMNs should be removed because of their higher risk of developing invasive cancer. Once resected, they must be extensively sampled or, much better, submitted in its entirety for microscopic study to completely rule out associated invasive carcinoma.

Classification, morphology and molecular pathology of premalignant lesions of the pancreas

Over the past few years there have been substantial advances in our knowledge of premalignant lesions of the pancreas. Given the dismal prognosis of untreated pancreatic cancer, and the small proportion of patients who are operative candidates, an understanding of these premalignant lesions is essential for the development of strategies for early diagnosis and prevention. The 2010 WHO classification has added new entities, including intraductal tubular papillary neoplasms (ITPNs), and clarified the nomenclature and grading of previously recognised precursor lesions of pancreatic adenocarcinoma, such as intraductal papillary mucinous neoplasms (IPMNs), mucinous cystic neoplasms (MCNs) and pancreatic intraepithelial neoplasia (PanIN). In particular, there has been an upsurge of interest in the natural history of IPMN, driven partly by improvements in imaging modalities and the consequent apparent increase in their incidence, and partly by recognition that subtypes based on location or histological appearance define groups with significantly different behaviours. In mid 2012 revised international guidelines for the classification and management of IPMNs and MCNs were published, although in several respects these guidelines represent a consensus view rather than being evidence-based. In recent years major advances in molecular technologies, including whole-exome sequencing, have significantly enhanced our knowledge of pancreatic premalignancy and have identified potentially highly specific diagnostic biomarkers such as mutations in GNAS and RNF43 that could be used to pre-operatively assess pancreatic cysts.

[Pathology and classification of intraductal papillary mucinous neoplasms of the pancreas]

Intraductal papillary mucinous neoplasms (IPMN) are precursor lesions of ductal adenocarcinoma of the pancreas and one of the most common cystic entities in this organ. Branch and main duct types are further distinguished based on the tumor localization. An additional classification is based on the predominant architecture and immunohistochemical profile with four prognostic relevant subtypes, gastric, intestinal, pancreato-biliary and oncocytic. This review provides an overview about the malignant potential of the different subtypes and the prognosis of associated invasive tumors and gives recommendations for the pathological assessment of resection specimens with IPMNs.

Intraoperative pancreatoscopy with narrow band imaging: a novel method for assessment of resection margins in case of intraductal papillary mucinous neoplasm

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) is characterized by intraductal proliferation of neoplastic mucinous cells with a variable extent along the main duct or its branches. The lesion may be continuous or discontinuous. Skip lesions have been described in about 6-19% of cases. Complete resection without leaving behind any skip lesions is important, to such an extent that many groups suggest even total pancreatectomy, a major and morbid surgery.

METHODS

A 40 year-male patient with chronic pancreatitis presented with recent-onset diabetes mellitus and weight loss. Ultrasound and computed tomography (CT) scan showed a cystic lesion in the head and uncinate process of pancreas. Peroral pancreatoscopy showed villous projections with dilated tortuous vessel in the head, suspicious of IPMN. The duct beyond pancreatic head could not be visualized and remained unassessed. At pancreatoduodenectomy, pancreatoscopy with narrow band imaging (NBI) was done using flexible pancreatoscope through the cut end of the duct at the neck to assess the duct in the body and tail.

RESULTS

Pancreatoscopy with NBI showed a normal-looking resection margin and a skip lesion 1 cm beyond it. The revised resection margin confirmed the skip lesion on frozen section and also that the fresh cut margin was negative. The remaining duct in the body and tail was normal on pancreatoscopy. Total clearance of the disease could be achieved without a major procedure such as total pancreatectomy.

CONCLUSIONS

Intraoperative pancreatoscopy, especially with NBI, is a good diagnostic tool for IPMN and also helps in intraoperative decision-making of the resection margins.

Imaging IPMN: take home messages and news

IPMN is a frequent disease involving pancreatic duct. This disease could be malignant (parenchymal invasive adenocarcinoma), particularly if the main pancreatic duct is involved (this involvement is considered present if > 6 mm), if this enlargement reaches 10 mm or more, and if the pathological phenotype is biliopancreatic or intestinal (malignancy is less frequent if gastric one). Invasiveness is suspected if hypodense parenchymal lesion is present, particularly near a cystical lesion or MPD, a mural nodule of the wall, or if MPD wall has got a contrast uptake. Mural nodules inside cystic branch duct are associated with in situ grade 3 malignancies. MPD IPMN must be resected to prevent malignancy. The follow-up of isolated branch duct cysts relies upon MDCT and MRI, every two years if lesion is less than 1cm. Every one year if bigger, particularly if more than to 3 cm.

Intraductal papillary mucinous neoplasm: Coming of age

Intraductal papillary mucinous neoplasm (IPMN) is a disease in evolution. Since its first description almost 30 years ago, a better understanding of the disease has steadily accrued. Yet, there are numerous challenges still for clinicians who treat this fascinating disease. A group of leading content experts on IPMN was assembled and charged with presenting cutting-edge knowledge on various topics for which they have considerable experience. This manuscript provides an historical perspective of both clinical and biological quandaries that have been resolved to date. Furthermore, it poses new avenues for investigation while highlighting the contributions of the various authors to this collective review.