Management of incidental pancreatic cysts: which guidelines?

Sequential molecular and cytologic analyses provides a complementary approach to the diagnosis of pancreatic cystic lesions: a decade of clinical practice

INTRODUCTION

Many pancreatic cystic lesions (PCL) are of neoplastic nature with potential to progress to pancreatic adenocarcinoma. Early stratification of patients to either clinical observation or surgical intervention can considerably increase the survival rate. Recent studies have shown the value of molecular analysis to current diagnostic modalities.The aim of this study is to evaluate the diagnostic improvement by utilizing multiple sequential cytologic and molecular cyst fluid analyses.

MATERIALS AND METHODS

We prospectively evaluated 58 patients for whom multiple endoscopic ultrasound-guided fine-needle aspiration of cyst fluid specimens were available. Specimens were subjected to next generation sequencing to identify any recurrent gene mutations commonly found in PCL. The molecular findings were compared with cytologic and final diagnoses.

RESULTS

Cytologic diagnoses were classified into 3 groups: non-diagnostic (first visit: 33.9%, cumulative: 15.8%, P = 0.03), negative (1st visit: 53.6%, cumulative: 56.1%, P = 0.85) and atypical/suspicious/positive (first visit: 12.5%, cumulative: 28.1%, P = 0.06). The mutational analyses were clustered into indeterminate/failure (first visit: 1.7%, cumulative: 0%), KRAS/GNAS/VHL group (first visit: 50.0%, cumulative: 53.4%) and any mutation (first visit: 50.0%, cumulative: 53.4%). Mutational analysis identifies up to 72% and 71% whereas cytologic analysis classified up to 46% and 63% of lesions correctly in first and multiple visits, respectively.

CONCLUSIONS

The cytology and molecular analyses provide a complementary approach to patients with PCL. Power of molecular analysis in detection of a neoplastic lesion is significantly higher in one visit (P = 0.01) with comparable detection rates (P = 0.43) for both cytologic and molecular analyses after multiple visits.

Abdominal Imaging of Pancreatic Cysts and Cyst-Associated Pancreatic Cancer in BRCA1/2 Mutation Carriers: A Retrospective Cross-Sectional Study

BACKGROUND

Direct-to-consumer BRCA testing will increase BRCA diagnoses and subsequent abdominal imaging. It is unclear whether BRCA carriers are at higher risk of developing pancreatic cysts (PCs) or cyst-associated pancreatic ductal adenocarcinoma (PDAC). We investigated the prevalence of PCs in BRCA-tested patients, and whether BRCA-carriers have higher rates of PDAC when PCs are found.

STUDY DESIGN

This is a retrospective cross-sectional study of patients with BRCA testing and abdominal imaging between 1996 and 2018. Pancreatic cysts were identified on original imaging reports. Prevalence and risk characteristics of PCs, as well as incidence of PDAC, were compared between BRCA+, BRCA-, and BRCA-untested patients.

RESULTS

Pancreatic cysts were identified in 4,045 patients among 128,164 unique patients with abdominal imaging, including 33 patients with PCs in 1,113 BRCA-tested patients. There was no difference in PC prevalence between BRCA+, BRCA-, and untested patients (3.6%, 2.6%, 3.2%, respectively; p = 0.64). Pancreatic cysts were diagnosed in BRCA+ patients at a younger age (57.1 vs 65.3 years, p < 0.001); however, there was no difference in risk stratification compared with BRCA- or untested patients by consensus criteria. Across the population of imaged patients, patients with PCs had significantly higher rates of PDAC compared with those without PCs (18.2% vs 2.4%, p < 0.001). Incidence of cyst-associated PDAC was similar in BRCA+ and BRCA- patients (13.3% vs 22.2%, p = 0.84).

CONCLUSIONS

BRCA+ patients have similar rates of PCs, high-risk features in their cysts, and PDAC as BRCA- and untested patients. BRCA+ patients likely do not require dedicated abdominal imaging to evaluate for PCs and should follow management guidelines similar to those as the untested general population if an incidental PC is identified.

Does cyst growth predict malignancy in branch duct intraductal papillary mucinous neoplasms? Results of a large multicenter experience

BACKGROUND

Cyst growth of BD-IPMNs on follow-up imaging remains a concerning sign.

AIMS

To describe cyst size changes over time in BD-IPMNs, and determine whether cyst growth rate is associated with increased risk of malignancy.

METHODS

This is a retrospective study performed at two high volume tertiary centers. Mean cyst size at baseline (MCSB) and mean growth rate percentage (MGRP) were calculated. Rapid cyst growth was defined as MGRP ≥30%/year. Patient and cyst related characteristics were studied.

RESULTS

160 patients were followed for a median of 27.4 (12-114.5) months. MCSB was 15.1 ± 8.0 mm. During follow-up, 73 (45.6%) showed any cyst size increase, of which 15 cysts (9.4%) exhibited MGRP ≥30%/year. Rapid cyst growth was not associated with patient or cyst characteristics. Cyst fluid molecular analysis from 101 cysts showed KRAS mutation in 26. Compared to KRAS-negative cysts, neither MCSB (16.0 mm vs. 17.7 mm; p = 0.3) nor MGRP (3.9%/year vs. 5.8%/year; p = 0.7) was significantly different. Eighteen patients underwent surgery; 15 (83%) had LGD, and 3 had advanced neoplasia. Two cysts with LGD and one cyst with advanced neoplasia had MGRP ≥30%/year.

CONCLUSION

Increase in BD-IPMNs size was not associated with the known high risk patient or cyst-related characteristics. Rapid growth of BD-IPMNs was not associated with advanced neoplasia on surgical pathology.

Preoperative Evaluation of a Pancreas Mass: Diagnostic Options

As modern abdominal imaging equipment advances, pancreatic lesion detection improves. Most of these lesions are incidental, and present a conundrum to the clinician and create great anxiety to the patient until a final diagnosis is made. For the practicing physician, the plethora of diagnostic options is overwhelming. The relevant question is, what is the most efficient algorithm to follow and to arrive at a timely and accurate diagnosis. This article presents a logical approach to the initial evaluation of a pancreatic lesion to get the most information possible with the least amount of testing, and to avoid duplicative measures.