Prevalence and progression of intraductal papillary mucinous neoplasms of the pancreas in solid organ transplant recipients: A systematic review

Frozen section pathology in IPMN: A systematic review

Intraductal papillary mucinous neoplasms (IPMNs) resection margins are assessed intraoperatively using frozen section (IFS) pathology. We conducted a systematic review to evaluate the concordance of IFS with permanent histopathology and the association between IFS margin status and recurrence. A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We queried PubMed, Embase, Scopus, and Google Scholar for studies reporting IFS in patients undergoing resection for IPMN. Data, including IFS margin status, recurrence rates, and final pathology, were extracted. Positive margins were defined as high-grade dysplasia or invasive cancer. Seven studies, with a total of 706 patients, met the inclusion criteria. Positive IFS margins were reported in 9.4% of cases, with a high correlation (98%) between IFS and final pathology. Recurrence occurred in 15.4% of patients. Fifty-nine of 85 (69.4%) patients with recurrence of IPMN or intraductal papillary mucinous carcinoma (IPMC) had negative IFS margins. IFS accurately predicts final pathology and is a valuable tool for guiding intraoperative decision-making. A sizeable number of patients experienced recurrence despite negative margins, highlighting the need for adjunct diagnostic modalities and continued surveillance following resection, regardless of margin status.

Disease progression of side-branch intraductal papillary mucinous neoplasms following solid organ transplant

BACKGROUND

Branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) are becoming more prevalent with advanced medical imaging and account for most of pancreatic cystic neoplasms (PCNs). Most incidental lesions should be surveyed, with resection reserved for specific, high-risk cases. Solid organ transplantation candidates may be high risk of resection before transplant and will require systemic immunosuppression after transplant, which has been theorized to alter the natural history of the IPMN. We aimed to describe the progression in surveilled cysts after solid organ transplantation.

METHODS

A prospectively maintained database of PCNs was queried for patients with IPMN. Patients who had received a previous solid organ transplantation and with ≥2 imaging studies >6 months apart after transplantation were included. Clinically relevant (CR) progression was defined as symptoms, worrisome/high-risk stigmata, or invasive carcinoma (IC). Growth ≥5 mm in 2 years is considered CR progression; size ≥3 cm alone is not.

RESULTS

Between 1997 and 2023, 252 patients received solid organ transplantation (liver, 86; kidney, 113; and lung, 54) and were diagnosed as having an IPMN. This cohort was compared with a set of 770 patients surveilled for IPMN who did not have previous transplantation. Median follow-up period was 3.7 years (IQR, 1.6-6.8). Moreover, 2 transplant patients (0.8%) developed IC, and 4 developed (1.6%) high-grade dysplasia (HGD). Both were less common in transplant patients than the nontransplant population (IC, 3.3%; HGD, 2.9%), although this was not significant on time-to-event analysis (IC, P = .152; HGD, P = .352). The rate of CR progression was high in the transplant cohort (n = 118; 47%). Features of CR progression included size growth (n = 79; 67%), other worrisome/high-risk stigmata (n = 25; 21%), and new main duct involvement (n = 14; 12%). Compared with the nontransplant (n = 128; 17%), transplant patients had a higher rate of CR progression (P < .001), which was mostly explained by a more frequent size growth (31% vs 9%; P < .001). However, no transplant patients with size growth CR progression developed IC. Moreover, 17 (6.7%) required pancreatic surgery for CR progression after transplant vs 58 (7.5%) in the nontransplant population. Furthermore, 6 resected cysts (35%) harbored high-risk pathology after transplant (IC, 2; HGD, 4) vs 40 (69%) in the general population (P < .001; IC, 29; HGD, 11).

CONCLUSION

Malignant transformation of BD-IPMNs is rare despite systemic immunosuppression in solid organ transplant patients. This supports transplantation in patients with IPMN without fear of worsening their risk of pancreatic cancer, although it was associated with a higher risk of disease progression. Patients with IPMNs should be surveilled with yearly scans after transplant, with pancreatic resection reserved for only high-risk features as we continue to define the optimal criteria for those with CR progression.

Progression of Intraductal Papillary Mucinous Neoplasms of the Pancreas After Liver Transplantation

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) are the most commonly identified pancreatic cystic neoplasms. Incidentally detected IPMNs are common among liver transplant recipients. The risk of IPMN progression to pancreatic cancer in transplant recipients and the impact of immunosuppression on the risk of malignant transformation of IPMN are unclear.

METHODS

In this retrospective study of consecutive liver transplant recipients across Mayo Clinic over a 13-year period, patients were assessed for possible IPMN by automated chart review. Pancreatic cystic lesions were characterized as suspected IPMNs based on imaging criteria. Cox proportional hazards models were used to determine the association between IPMN progression (the development of cancer or worrisome features) and clinical and immunosuppression regimen characteristics.

RESULTS

Of 146 patients with suspected IPMNs, progression occurred in 7 patients (2 cases of IPMN-associated cancer and 5 cases of worrisome features) over an average follow-up of 66.6 months. Immunosuppression type, medication number, and tacrolimus trough levels were not associated with IPMN progression (p > 0.05). Combined kidney and liver transplantation (p = 0.005) and pretransplant cholangiocarcinoma (p = 0.012) were associated with IPMN progression.

CONCLUSION

IPMN progression is rare after liver transplantation even over an extended follow-up period. The findings were notable for the absence of an association between IPMN progression and immunosuppression regimen. Larger studies are needed given the low incidence.

Premalignant Lesions in the Kidney Transplant Candidate

End-stage kidney disease patients who are referred for transplant undergo an extensive evaluation process to ensure their health prior to transplant due in part to the shortage of available organs. Although management and surveillance guidelines exist for malignancies identified in the transplant and waitlist populations, less is written about the management of premalignant lesions in this population. This review covers the less common premalignant lesions (intraductal papillary mucinous neoplasm, gastrointestinal stromal tumor, thymoma, and pancreatic neuroendocrine tumor) that can be found in the transplant candidate population. High-level evidence for the management of these rarer premalignant lesions in the transplant population is lacking, and this review extrapolates evidence from the general population and should not be a substitute for a multidisciplinary discussion with medical and surgical oncologists.

Surveillance of Pancreatic Cystic Neoplasms

Pancreatic cystic neoplasms (PCNs) are increasingly detected because of the widespread use of cross-sectional imaging and overall aging population. While the majority of these cysts are benign, some can progress to advanced neoplasia (defined as high-grade dysplasia and invasive cancer). As the only widely accepted treatment for PCNs with advanced neoplasia is surgical resection, accurate preoperative diagnosis, and stratification of malignant potential for deciding about surgery, surveillance or doing nothing remains a clinical challenge. Surveillance strategies for pancreatic cysts (PCNs) combine clinical evaluation and imaging to assess changes in cyst morphology and symptoms that may indicate advanced neoplasia. PCN surveillance heavily relies on various consensus clinical guidelines that focus on high-risk morphology, surgical indications, and surveillance intervals and modalities. This review will focus on current concepts in the surveillance of newly diagnosed PCNs, especially on low-risk presumed intraductal papillary mucinous neoplasms (those without worrisome features and high-risk stigmata), and appraise current clinical surveillance guidelines.