Intraoperative irrigation cytology of the remnant pancreas to detect remnant distinct pancreatic ductal adenocarcinoma in patients with intraductal papillary mucinous neoplasm undergoing partial pancreatectomy

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.

Intraductal papillary mucinous neoplasm of the pancreas: Cytomorphology, imaging, molecular profile, and prognosis

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) constitutes up to 20% of all pancreatic resections, and has been increasing in recent years. Histomorphological findings of IPMN are well established; however, there are not many published papers regarding the cytological findings of IPMN on fine needle aspiration (FNA) specimens. We review the cytomorphological features, molecular profile, imaging findings, and prognosis of IPMN.

METHODS

The English literature was thoroughly searched with key phrases containing IPMN.

OBSERVATIONS

IPMN is a rare entity, affecting men and women equally and is usually diagnosed at the age of 60-70 years. The characteristic imaging features include a cystic lesion with associated dilatation of the main or branch pancreatic duct, and atrophy of surrounding pancreatic parenchyma. Cytomorphological features of IPMN include papillary fragments of mucinous epithelium in a background of abundant thick extracellular mucin, a hallmark feature. IPMNs should be evaluated for high-grade dysplasia, which manifests with nuclear atypia, nuclear moulding, prominent nucleoli, nuclear irregularity, and cellular crowding. Molecular profiling of IPMN along with carcinoembryonic antigen and amylase levels is useful in predicting malignancy or high-grade dysplasia arising in IPMN. Overall, the prognosis of IPMN is excellent except in those cases with high-grade dysplasia and malignant transformation. Postoperative surveillance is required for resected IPMNs.

CONCLUSION

IPMN requires a multidisciplinary approach for management. Cytomorphological findings of IPMN on FNA, in conjunction with tumour markers in pancreatic fluid cytology and imaging findings, are of paramount importance in clinical decision-making for IPMN.

Clinical Management and Surgical Decision-Making of IPMN of the Pancreas

Intraductal papillary mucinous neoplasm (IPMN) is the most common pancreatic cystic neoplasm (PCN). The increased attention to IPMN is due to its unique features of malignant progression, being different between main duct IPMN and branch duct IPMN, and increased de novo development of conventional pancreatic ductal adenocarcinoma elsewhere in the pancreas. The increased interest in IPMN led to publication of many guidelines on its clinical management. This chapter aims to summarize and compare characteristics of nine guidelines on the clinical management of IPMN and other PCNs published in the English literature and further to show a current strategy for surgical decision making in the management of IPMN.

Surveillance of patients with intraductal papillary mucinous neoplasm with and without pancreatectomy with special reference to the incidence of concomitant pancreatic ductal adenocarcinoma

BACKGROUND

The presence of an intraductal papillary mucinous neoplasm is important in the detection of concomitant pancreatic ductal adenocarcinoma. The aim of this study was to elucidate the incidence and timing of development of concomitant pancreatic ductal adenocarcinoma in patients with and without pancreatectomy for intraductal papillary mucinous neoplasm.

METHODS

We reviewed retrospectively the surveillance data for 22 patients who underwent pancreatectomy for pancreatic ductal adenocarcinoma concomitant with intraductal papillary mucinous neoplasm (pancreatic ductal adenocarcinoma-resection group), 180 who underwent pancreatectomy for intraductal papillary mucinous neoplasm (intraductal papillary mucinous neoplasm-resection group), and 263 whose intraductal papillary mucinous neoplasms were left untreated (nonresection group). The incidence and timing of the development of a concomitant pancreatic ductal adenocarcinoma during the surveillance of patients with and without partial pancreatectomy for intraductal papillary mucinous neoplasm were investigated using the Kaplan-Meier method.

RESULTS

During a median surveillance period of 40 months (range 6-262 months), 5 patients in the pancreatic ductal adenocarcinoma-resection group, 6 in the intraductal papillary mucinous neoplasm-resection group, and 8 in the nonresection group developed concomitant pancreatic ductal adenocarcinoma. The estimated 5-year (17%) and 10-year (56%) cumulative incidences of secondary pancreatic ductal adenocarcinoma in the pancreatic ductal adenocarcinoma-resection group were significantly greater than those in the other two groups (P < .01). Conversely, the difference in the estimated cumulative incidence of concomitant pancreatic ductal adenocarcinoma between the intraductal papillary mucinous neoplasm-resection and nonresection groups was not significant (5-year, 5.0% vs 2.2%; 10-year, 5.0% vs 8.7%; P = .87).

CONCLUSION

Long-term (≥5-year) surveillance in patients with intraductal papillary mucinous neoplasm is necessary and important because of the potential for development of concomitant pancreatic ductal adenocarcinoma. Those with a history of resection of concomitant pancreatic ductal adenocarcinoma at the time of the initial operation are at quite high risk for the development of secondary pancreatic ductal adenocarcinoma.

Intraductal papillary mucinous neoplasm of the pancreas - epidemiology, risk factors, diagnosis, and management

Intraductal papillary mucinous neoplasm (IPMN) is one of the most common cystic neoplasms of the pancreas. It is a heterogeneous disease and can be divided into ductal types and morphological subtypes. The incidence of IPMN is increasing, likely due to the widespread use of cross-sectional imaging and a growing elderly population. IPMN poses an increasing demand on the health care system. Current guidelines provide indications for surgery and recommendations for surveillance, but management of IPMN is still challenging in routine clinical practice. In this article, we review current knowledge about IPMN and provide future directions for improving diagnosis and management.

Revisions of international consensus Fukuoka guidelines for the management of IPMN of the pancreas

The management of intraductal papillary mucinous neoplasm (IPMN) continues to evolve. In particular, the indications for resection of branch duct IPMN have changed from early resection to more deliberate observation as proposed by the international consensus guidelines of 2006 and 2012. Another guideline proposed by the American Gastroenterological Association in 2015 restricted indications for surgery more stringently and recommended physicians to stop surveillance if no significant change had occurred in a pancreatic cyst after five years of surveillance, or if a patient underwent resection and a non-malignant IPMN was found. Whether or not it is safe to do so, as well as the method and interval of surveillance, has generated substantial debate. Based on a consensus symposium held during the meeting of the International Association of Pancreatology in Sendai, Japan, in 2016, the working group has revised the guidelines regarding prediction of invasive carcinoma and high-grade dysplasia, surveillance, and postoperative follow-up of IPMN. As the working group did not recognize the need for major revisions of the guidelines, we made only minor revisions and added most recent articles where appropriate. The present guidelines include updated information and recommendations based on our current understanding, and highlight issues that remain controversial or where further research is required.

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.

Thirty years of experience with intraductal papillary mucinous neoplasm of the pancreas: from discovery to international consensus

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is characterized by intraductal papillary proliferation of mucin-producing epithelial cells that exhibit various degrees of dysplasia. IPMN is classified as the main duct type (MD-IPMN) and the branch duct type (BD-IPMN) according to the location of involvement, and into four histological subtypes (gastric, intestinal, pancreatobiliary, and oncocytic) according to the histomorphological and immunohistochemical characteristics. Mucin core protein expression correlates with the biological behavior and prognosis of the tumor. DNA analysis has shown that IPMN is associated with a number of gene mutations, but the roles of many of these mutations require further investigation. Most patients with MD-IPMN undergo tumor resection. Patients with BD-IPMN who do not undergo resection may develop malignant change, and concomitant separate pancreatic cancer occurs in 2-10% of patients with IPMN. Patients with a strong family history may develop multiple BD-IPMNs as well as concomitant pancreatic cancer. Malignant changes are relatively easy to detect, especially by endoscopic ultrasonography (EUS), but the optimal surveillance protocol is currently unclear.

KEY MESSAGES

The 2012 guidelines for the management of IPMN recommend that patients with 'high-risk stigmata' (obstructive jaundice, enhanced solid component, and main pancreatic duct size ≥10 mm) should undergo resection. Patients with 'worrisome features' (cyst size ≥3 cm, thickened enhanced cyst walls, non-enhanced mural nodules, main pancreatic duct size 5-9 mm, abrupt change in main pancreatic duct caliber with distal pancreatic atrophy, lymphadenopathy, and clinical acute pancreatitis) should be evaluated by EUS. EUS is a more sensitive test than computed tomography or magnetic resonance imaging for the early detection of malignancy.

CONCLUSIONS

Most patients with MD-IPMN should undergo tumor resection. Patients with BD-IPMN who do not undergo resection should undergo careful surveillance including EUS for the early detection of malignant change and separate pancreatic cancer.

Current roles of endoscopy in the management of intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is characterized by intraductal papillary proliferation of mucin-producing epithelial cells that exhibit various degrees of dysplasia. IPMN is classified into four histological subtypes (gastric, intestinal, pancreatobiliary, and oncocytic) according to its histomorphological and immunohistochemical characteristics. Endoscopic retrograde cholangiopancreatography plays a crucial role in the evaluation of these features of IPMN. Endoscopic ultrasonography (EUS) has proven to be more sensitive than computed tomography or magnetic resonance imaging for early detection of malignancy. The present review addresses the current roles of endoscopy and related techniques in the management of IPMN. The particular focus is on diagnosing IPMN and malignancy within IPMN, detecting pancreatic cancer concomitant with IPMN, differentiating the epithelial subtypes of IPMN, determining the optimal strategy for the management of branch duct IPMN, and discussing innovative endoscopic technology related to IPMN. The disadvantages of endoscopic examinations of IPMN and different attitudes toward EUS-guided fine-needle aspiration for IPMN between Japan (negative) and other countries (active) are also discussed.

Navigation surgery using an augmented reality for pancreatectomy

AIM

The aim of this study was to evaluate the utility of navigation surgery using augmented reality technology (AR-based NS) for pancreatectomy.

METHODS

The 3D reconstructed images from CT were created by segmentation. The initial registration was performed by using the optical location sensor. The reconstructed images were superimposed onto the real organs in the monitor display. Of the 19 patients who had undergone hepatobiliary and pancreatic surgery using AR-based NS, the accuracy, visualization ability, and utility of our system were assessed in five cases with pancreatectomy.

RESULTS

The position of each organ in the surface-rendering image corresponded almost to that of the actual organ. Reference to the display image allowed for safe dissection while preserving the adjacent vessels or organs. The locations of the lesions and resection line on the targeted organ were overlaid on the operating field. The initial mean registration error was improved to approximately 5 mm by our refinements. However, several problems such as registration accuracy, portability and cost still remain.

CONCLUSION

AR-based NS contributed to accurate and effective surgical resection in pancreatectomy. The pancreas appears to be a suitable organ for further investigations. This technology is promising to improve surgical quality, training, and education.