Treatment of branch-duct intraductal papillary mucinous neoplasms of the pancreas: state of the art

Risk Assessment and Radiomics Analysis in Magnetic Resonance Imaging of Pancreatic Intraductal Papillary Mucinous Neoplasms (IPMN)

Intraductal papillary mucinous neoplasms (IPMNs) are a very common incidental finding during patient radiological assessment. These lesions may progress from low-grade dysplasia (LGD) to high-grade dysplasia (HGD) and even pancreatic cancer. The IPMN progression risk grows with time, so discontinuation of surveillance is not recommended. It is very important to identify imaging features that suggest LGD of IPMNs, and thus, distinguish lesions that only require careful surveillance from those that need surgical resection. It is important to know the management guidelines and especially the indications for surgery, to be able to point out in the report the findings that suggest malignant degeneration. The imaging tools employed for diagnosis and risk assessment are Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) with contrast medium. According to the latest European guidelines, MRI is the method of choice for the diagnosis and follow-up of patients with IPMN since this tool has a highest sensitivity in detecting mural nodules and intra-cystic septa. It plays a key role in the diagnosis of worrisome features and high-risk stigmata, which are associated with IPMNs malignant degeneration. Nowadays, the main limit of diagnostic tools is the ability to identify the precursor of pancreatic cancer. In this context, increasing attention is being given to artificial intelligence (AI) and radiomics analysis. However, these tools remain in an exploratory phase, considering the limitations of currently published studies. Key limits include noncompliance with AI best practices, radiomics workflow standardization, and clear reporting of study methodology, including segmentation and data balancing. In the radiological report it is useful to note the type of IPMN so as the morphological features, size, rate growth, wall, septa and mural nodules, on which the indications for surveillance and surgery are based. These features should be reported so as the surveillance time should be suggested according to guidelines.

Clinical Implication of Preoperative C-Reactive Protein/Albumin Ratio in Malignant Transformation of Intraductal Papillary Mucinous Neoplasm: A Propensity Score Analysis

Background: Inflammation-based scoring has been reported to be useful for predicting the recurrence and prognosis of various carcinomas. This study retrospectively investigated the relationship between inflammation-based score and intraductal papillary mucinous neoplasms (IPMNs). Methods: Between January 2013 and October 2018, we enrolled 417 consecutive patients with pancreatic tumors who received surgical resections at our hospital. The main outcome was the association between the preoperative inflammation-based score and their accuracy in predicting malignant transformation of IPMN. Results: Seventy six patients were eligible. Pathological findings indicated that 35 patients had low-grade dysplasia, 18 had high-grade dysplasia, and 23 had invasive carcinomas. As the C-reactive protein albumin ratio (CAR) was higher, malignant transformation of IPMNs also increased (p = 0.007). In comparing CAR^high and CAR^low using cutoff value, the results using a propensity score analysis showed that the CAR^high group predicted malignant transformation of IPMNs (odds ratio, 4.18; 95% confidence interval, 1.37–12.8; p = 0.01). In the CAR^high group, disease-free survival (DFS) was significantly shorter (p = 0.04). In the worrisome features, the AUC for the accuracy of malignant transformation with CAR^high was 0.84 when combining with the MPD findings. Conclusions: Preoperative CAR could be a predictive marker of malignant transformation of IPMNs.

Sonographic characteristics and follow-up of pancreatic cysts

OBJECTIVES

To assess sonographic characteristics and outcome of patients with pancreatic cystic lesions seen by ultrasound.

METHODS

From our ultrasound electronic reporting database we identified all patients in which "pancreatic cyst" or "pancreatic cysts" were reported from 1995 to 2018. In patients with more than one sonogram, the first was used for our study. For each case, we recorded sonographic characteristics, maximal diameter, cyst location, and results of follow-up ultrasound, CT or magnetic resonance imaging, as well as patient sex, age, relative clinical history, and endoscopic ultrasound (EUS) or surgical findings when available.

RESULTS

Our study included 177 patients of whom 121 were female (68.4%). Mean age at diagnosis was 65 (±16, SD, range 22-99). Ultrasound was the initial diagnostic test in 122 (68.9%). Mean diameter of the index cyst was 13.7 mm (±11.5 mm, SD, range 2-91 mm). Among 177 index cysts, 155 were simple and 22 complex. Three complex cysts were surgically resected, yielding a primary pancreatic malignancy, a metastasis, and an epithelial-lined cyst. One simple cyst was resected, yielding a benign intraductal papillary mucinous neoplasm. Seventeen patients underwent EUS showing six mucinous cysts and 11 nonmucinous cysts. One hundred-eighteen patients had follow-up imaging for a mean time of 5.6 years (±3.8, range 0.25-21 years). One patient was presumed to have primary pancreatic cancer. The overall rate for primary pancreatic malignancy was 1.7% (2/118).

CONCLUSIONS

Cystic pancreatic lesions seen on ultrasound are most often benign, with a low risk of pancreatic malignancy. Ultrasound is an excellent method to follow-up these cysts.

Diagnosis and management of intraductal papillary mucinous neoplasms of the pancreas

Background and aim of the work: Intraductal papillary mucinous neoplasms (IPMN) of the pancreas are cystic lesions with malignant potential. Given their increasing incidence in the latest years, a precise characterization and management of these lesions have become more and more crucial: even though the majority of IPMN has a benign and indolent course, it is fundamental to early recognize and stratify patients in order to accurately plan a tailored follow-up and to individuate those that would benefit of surgical treatment. The aim of this paper is to highlight the most recent evidence on IPMN available in the current literature. Methods: We performed a review of the recent literature and of the recent guidelines about pancreatic cystic lesions, especially IPMN. Results: The incidence of IPMN is now on the rise: an increasing number of patients, possibly because of the increasing diagnostic yield of imaging techniques, is being diagnosed with pancreatic cystic lesions, a great part of which are IPMN. The possibility of malignant transformation requires a careful approach to these patients, in the need of tailoring the follow-up and the therapy. Conclusion: A detailed diagnosis, the determination of risk factors for malignant transformation and a multisciplinary approach are of foremost importance for an effective management of IPMN. (www.actabiomedica.it)

Intraductal papillary mucinous neoplasms of the pancreas: a clinical challenge

The incidental detection rate of intraductal papillary mucinous neoplasms (IPMNs) has significantly increased. However, little is known about the natural history of these tumors. Their optimal management and appropriate follow-up are still unclear. We have, therefore, reviewed the available literature on IPMN focusing on their diagnosis, treatment according to the risk of malignant transformation, and follow-up. Areas covered: Bibliographical searches were performed in PubMed for the terms 'intraductal papillary mucinous neoplasm' and 'natural history' and 'diagnosis' and 'treatment' and 'surgery' and 'follow-up' and 'prognosis.' PubMed was used to search for all the relevant articles published over the last 10 years. A total of 7244 records were identified. After filtering for year range, English language, human studies, article types, and removing duplicates, 74 articles were left with the strongest level of evidence. Expert commentary: Available guidelines for IPMN management are mainly based on expert opinions and may lack strong evidence. Further studies are warranted to better predict the risk of recurrence/future malignancy and to establish standardized guidelines. IPMNs management should be based on multidisciplinary discussion and treatment should be tailored to an individual patient according to patient and tumor characteristics.

Identification of a pyruvate-to-lactate signature in pancreatic intraductal papillary mucinous neoplasms

OBJECTIVE

We used transcriptomic profiling and immunohistochemistry (IHC) to search for a functional imaging strategy to resolve common problems with morphological imaging of cystic neoplasms and benign cystic lesions of the pancreas.

METHODS

Resected pancreatic cancer (n = 21) and normal pancreas were laser-capture micro-dissected, and transcripts were quantified by RNAseq. Functional imaging targets were validated at the protein level by IHC on a pancreatic adenocarcinoma tissue microarray and a newly created tissue microarray of resected intraductal papillary mucinous neoplasms (IPMNs) and IPMN-associated adenocarcinomas.

RESULTS

Genes encoding proteins responsible for cellular import of pyruvate, export of lactate, and conversion of pyruvate to lactate were highly upregulated in pancreatic adenocarcinoma compared to normal pancreas. Strong expression of MCT4 and LDHA was observed by IHC in >90% of adenocarcinoma specimens. In IPMNs, the pyruvate-to-lactate signature was significantly elevated in high grade dysplasia (HGD) and IPMN-associated adenocarcinoma. Additionally, cores containing HGD and/or adenocarcinoma exhibited a higher number of peri-lesional stromal cells and a significant increase in peri-lesional stromal cell staining of LDHA and MCT4. Interestingly, the pyruvate-to-lactate signature was significantly upregulated in cores containing only low grade dysplasia (LGD) from patients with histologically confirmed IPMN-associated adenocarcinoma versus LGD cores from patients with non-invasive IPMNs.

CONCLUSION

Our results suggest prospective studies with hyperpolarized [1-13C]-pyruvate magnetic resonance spectroscopic imaging are warranted. If these IHC results translate to functional imaging findings, a positive pyruvate-to-lactate imaging signature might be a risk factor for invasion that would warrant resection of IPMNs in the absence of other worrisome features.