Accuracy and agreement of a large panel of endosonographers for endomicroscopy-guided virtual biopsy of pancreatic cystic lesions

BACKGROUND

Although emerging data evidences that EUS-guided needle-based confocal laser endomicroscopy (nCLE) accurately diagnoses pancreatic cystic lesions (PCLs), there are a lack of interobserver agreement (IOA) studies utilizing reference histopathological diagnosis and for specific PCL subtypes. Hence, we sought to assess the IOA, intra-observer reliability (IOR), and diagnostic performance of EUS-nCLE using a large cohort of patients with histopathological diagnosis amongst a broad panel of international observers.

METHODS

EUS-nCLE videos (n = 76) of subjects with PCLs [intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm (MCN), serous cystadenoma (SCA), pseudocyst, and cystic-neuroendocrine tumors/solid pseudopapillary neoplasm (cystic-NET/SPN)], simulating clinical prevalence rates were obtained from 3 prospective studies. An international panel of 13 endosonographers with nCLE experience, blinded to all PCL data, evaluated the video library twice with a two-week washout for PCL differentiation (mucinous vs. non-mucinous) and subtype diagnosis.

RESULTS

The IOA (κ = 0.82, 95% CI 0.77-0.87) and IOR (κ = 0.82, 95% CI 0.78-0.85) were "almost perfect" to differentiate mucinous vs. non-mucinous PCLs. For PCL subtype, IOA was highest for SCA (almost perfect; κ = 0.85), followed by IPMN (substantial, κ = 0.72), and cystic-NET/SPN (substantial, κ = 0.73). The IOA was moderate for MCN (κ = 0.47), and pseudocyst (κ = 0.57). Compared to histopathology, observers differentiated mucinous vs. non-mucinous PCLs with high accuracy (94.8%, 95% CI 93.3-96.1). For detecting specific PCLs subtypes, EUS-nCLE was highly accurate in diagnosing non-mucinous cysts (SCA: 98%; cystic-NET/SPN: 96%; pseudocyst: 96%) and slightly less accurate for mucinous lesions (IPMN: 86%; MCN: 84%).

CONCLUSION

Diagnosis of PCLs by EUS-nCLE guided virtual biopsy is very accurate and reliable for the most prevalent pancreatic cysts in clinical practice.

Genomic profile concordance between pancreatic cyst fluid and neoplastic tissue

BACKGROUND

DNA mutational analysis of pancreatic cystic fluid (CF) is a useful adjunct to the evaluation of pancreatic cysts. KRAS/GNAS or RAF/PTPRD/CTNNB1/RNF43 mutations are highly specific to precancerous or advanced neoplasia. Several studies recently demonstrated the ability of next-generation sequencing (NGS) analysis to detect DNA mutations in pancreatic CF, but few studies have performed a systematic comparative analysis between pancreatic CF and neoplastic surgical tissue (NT). The value of CF-NGS analysis indicators for determining surgical resection necessitates evaluation.

AIM

To confirm whether CF genomic profiles are a reliable malignancy predictor by comparing NGS mutational analyses of CF and NT.

METHODS

Patients requiring surgery for high-risk pancreatic cysts were included in a multicenter prospective pilot study. DNA from CF (collected by endoscopic ultrasound-guided fine needle aspiration (known as EUS-FNA)) and NT (collected by surgery) were analyzed by NGS. The primary objective was to compare the mutation profiles of paired DNA samples. The secondary objective was to correlate the presence of specific mutations (KRAS/GNAS, RAF/ PTPRD/CTNNB1/RNF43/POLD1/TP53) with a final cancer diagnosis. Sensitivity and specificity were also evaluated.

RESULTS

Between December 2016 and October 2017, 20 patients were included in this pilot study. Surgery was delayed for 3 patients. Concordant CF-NT genotypes were found in 15/17 paired DNA, with a higher proportion of mutated alleles in CF than in NT. NGS was possible for all pancreatic CF collected by EUS-FNA. In 2 cases, the presence of a KRAS/GNAS mutation was discordant between CF and NT. No mutations were found in 3 patients with NT or pancreatic cysts with high-grade dysplasia. The sensitivity and specificity of KRAS/GNAS mutations in CF to predict an appropriate indication for surgical resection were 0.78 and 0.62, respectively. The sensitivity and specificity of RAF/PTPRD/CTNNB1 /RNF43/POLD1/TP53 mutations in CF were 0.55 and 1.0, respectively.

CONCLUSION

Mutational analyses of CF and NT were highly concordant, confirming the value of NGS analysis of CF in the preoperative malignancy assessment. However, these results need to be confirmed on a larger scale.

Radiolucent pancreatic lithiasis: a precursor stage for calcified pancreatic lithiasis or a new entity?

OBJECTIVE

Radiolucent pancreatic lithiasis (RPL) has been identified as a different entity from calcified pancreatic lithiasis. The purpose of this study is to evaluate the frequency, characteristics and evolution of RPL.

PATIENTS

Between 1983 and 1995, 278 consecutive patients who presented with pancreatic lithiasis were studied. Forty-four patients had RPL (15.8%): 27 had pure radiolucent stones (PRS) (group 1), 5 had pure radiolucent stones combined with evenly calcified stones (ECS) (group 2), 2 had target calculi (TC) (radiolucent core with calcified shell) (group 3), 10 had TC combined with ECS (group 4).

RESULTS

Among the 27 patients with PRS, there were 19 males with a mean age of 41 years. PRS were mainly located in the head of the pancreas with a mean diameter of 5 mm (range 3-26 mm). Seven patients among 27 with PRS (26%) were less than 20 years old (juvenile form) or more than 60 years old (senile form). They were characterized by no or low alcohol consumption and a high rate of attacks of acute pancreatitis. In group 1, PRS turned to more advanced calcified stages in 6/16 of patients (37%) followed in 30 to 144 months with a prior stage of TC in 2 cases. An evolution toward more calcified stages (TC or ECS) occurred in half of the patients belonging to group 2 and 4 in 36 to 84 months. Genetic disposition and alcohol consumption could account for the evolution toward more calcified stages. A genetic factor is suggested by a rapid evolution to evenly calcified stones in two aged children 8 and 10 years and by a high frequency of familial cases in patients belonging to groups 2 and 4 (60% and 20%) as compared to group 1 with PRS (4%). Alcohol consumption could accelerate the calcifying process since patients belonging to groups 2 and 4 had a significantly higher alcohol consumption than those with PRS (group 1).

CONCLUSION

RPL is a heterogeneous pancreatic disease including juvenile and senile presentation which may represent about 15% of pancreatic lithiasis. Evolution towards calcified stages (PRS then TC then ECS) occurred in 37-50% of cases and could be related to a genetic factor and increased alcohol consumption.

Gallbladder abnormalities in medical ICU patients: an ultrasonographic study

Patients in the intensive care unit (ICU) have many risks factors for gallbladder stasis or acute acalculous cholecystitis (ACC), including fasting, total parenteral nutrition, sedation, mechanical ventilation, infection and shock. We have performed a prospective study to estimate the prevalence of ultrasonographic gallbladder abnormalities in 30 consecutive medical ICU patients during the first 2 days of their stay in the ICU. Two patients had previously undergone cholecystectomy and were excluded from the study. Seventeen (61%) of the remaining 28 patients presented with gallbladder abnormalities. Considering three major criteria of ACC, 14 patients (50%) presented with either sludge (25%), wall thickening (22%) or hydrops (11%). However, none of the patients needed a surgical procedure during the study because of gallbladder disease. We conclude that an important proportion of ICU patients presented with gallbladder abnormalities shown by ultrasonography and that this may have implications for establishing a diagnosis of ACC using ultrasonographic criteria.

Clinical course and morphological features of chronic calcifying pancreatitis associated with pancreas divisum

OBJECTIVES

To describe the clinical and radiological patterns of chronic calcifying pancreatitis (CCP) associated with pancreas divisum.

DESIGN

Case-control study.

METHODS

Pancreas divisum was diagnosed in 20 out of 411 patients presenting with CCP between 1985 and 1994 (group I). They were matched for age and sex with 20 patients presenting with CCP but without pancreas divisum (group II). The cause of CCP was presumed to be mainly chronic alcohol use, as 18 patients in each group had heavy alcohol consumption.

RESULTS

The age at onset of the disease was comparable in the two groups (mean 40.8 compared with 42.4 years, NS), and consumption of alcohol and tobacco did not differ. Pancreatic calcified calculi were seen on plain films of the abdomen in eight patients from group I and in 14 patients from group II (P = 0.05). Loss of weight (> 5 kg), diabetes, portal hypertension and the rate of complications of chronic pancreatitis were not significantly different in the two groups. The frequency of attacks of acute pancreatitis was similar (mean 0.9 compared with 1.2 per year, range 0.2-6.0 per year, NS). The occurrence of pseudocysts did not differ (11 compared with 15, NS). Pancreatograms were categorized using the Cambridge classification. No differences could be demonstrated between the two groups (chi 2, P = 0.15). In group I, pancreatographic abnormalities were located only in the ventral segment of the pancreas in three patients, only in the dorsal segment of the pancreas in nine patients and in the whole pancreas in six patients. In two patients, the ventral duct could not be demonstrated.

CONCLUSION

We conclude that pancreas divisum does not modify the natural course of CCP. In about one-half of cases, pancreatographic abnormalities may be segmental.