Comparative accuracy of endosonographic shear wave elastography and transcutaneous liver stiffness measurement: a pilot study.

BACKGROUND AND AIMS: Vibration-controlled transient elastography (VCTE) is a validated test for assessing liver fibrosis but may be unreliable in select patients, including those with morbid obesity. The limitations of VCTE may be overcome by EUS-guided shear wave elastography (EUS-SWE). METHODS: This single-center, prospective, nonrandomized tandem study compared the diagnostic accuracy of EUS-SWE and VCTE in consecutive patients undergoing liver biopsy sampling because of unreliable noninvasive testing. EUS-SWE of the left and right lobes were separately performed and then compared with VCTE. Liver elasticity cutoffs for different stages of fibrosis were estimated in 3 ways: optimized sensitivity and specificity using the Youden index; and with sensitivity and specificity fixed at 90% each, Diagnostic accuracy for fibrosis was compared with liver histology using the area under the receiver-operating characteristic curve (AUROC). The primary outcome was the diagnostic accuracy of EUS-SWE for advanced fibrosis. Secondary outcomes were diagnostic accuracy of VCTE, EUS-SWE for left and right hepatic lobes for significant/advanced fibrosis, and cirrhosis. RESULTS: Forty-two patients (39 men, aged 54.5 ± 12.1 years) underwent EUS-SWE, VCTE, and liver biopsy sampling. The cross-validated AUROCs for advanced fibrosis were as follows: VCTE, .87 (95% confidence interval [CI], .76-.97); EUS-SWE left lobe, .8 (95% CI, .64-.96); and EUS-SWE right lobe, .78 (95% CI, .62-.95). The corresponding AUROCs for cirrhosis were as follows: VCTE, .9 (95% CI, .83-.97); EUS-SWE left lobe, .96 (95% CI, .9-1); and EUS-SWE right lobe, .9 (95% CI, .8-1). VCTE was unreliable in 8 patients who successfully underwent EUS-SWE. There was no statistically significant difference in the AUROCs for EUS-SWE and VCTE. CONCLUSIONS: EUS-SWE correlates well with liver histology and is a safe and reliable diagnostic test for assessing liver fibrosis with accuracy comparable with VCTE. (Clinical trial registration number: NCT04533932.).

The utility of immunohistochemical testing for mismatch repair proteins in fine needle aspiration specimens of pancreatic adenocarcinoma.

INTRODUCTION: Microsatellite instability (MSI) testing is recommended for all colonic and endometrial carcinomas to screen for Lynch syndrome. The role of MSI testing in pancreatic adenocarcinoma has not been well-established. Screening can be done via immunohistochemical (IHC) staining for mismatch repair (MMR) proteins (MLH1, MSH2, MSH6, PMS2). We report our experience and the clinical utility of MMR IHC on pancreatic adenocarcinomas in fine-needle aspiration (FNA) specimens. MATERIALS AND METHODS: We performed a retrospective review to identify all patients diagnosed with pancreatic adenocarcinoma by FNA at our institution between December 2017 and September 2019. For cases with sufficient tumor cells for testing, the MMR results and morphology were summarized, as well as corresponding clinical information, including age, clinical stage, treatment, and concurrent other cancers. RESULTS: From December 2017 to September 2019, there were a total of 184 pancreatic FNAs with a diagnosis of adenocarcinoma. Of these 184 FNAs, 65 (35%) contained sufficient material in the cell block to perform IHC for MMR. The cell block material was collected in either RPMI or CytoLyt. Poor technical quality precluded interpretation of PMS2 in 4 cases and MSH6 in 2 cases. All other cases showed intact expression of all four proteins. CONCLUSIONS: IHC for MMR proteins can be done on specimens collected in RPMI or CytoLyt, but RPMI appears to be more reliable. None of the pancreatic adenocarcinomas in this study showed loss of MMR protein expression. Routine testing of MMR loss may not be indicated in pancreatic adenocarcinomas in the general patient population.