Concise review on the comparative efficacy of endoscopic ultrasound-guided fine-needle aspiration vs core biopsy in pancreatic masses, upper and lower gastrointestinal submucosal tumors

Solid Pseudopapillary Neoplasm of the Pancreas: Unfolding an Intriguing Condition

Pancreatic cancer is one of the most lethal malignant neoplasms, with a 1-year survival rate after diagnosis of 24%, and a 5-year survival rate of only 9%. While this illustrates the behavior of its main histologic type - ductal adenocarcinoma, there are other histologic subtypes of pancreatic cancer that can harbor excellent prognosis. Solid pseudopapillary neoplasm, described as a rare low-grade malignant neoplasm by the World Health Organization, is the best example of that, having an overall 5-year survival rate of about 97%. Not only the prognosis, but everything about this entity is unique: its histogenesis, epidemiology, presentation, imaging characteristics, cytology features, immunohistochemical profile, and treatment. This explains the urge to improve our understanding about this entity and thus our ability to accurately recognize and manage it. Having this in mind, this article aims to summarize the most relevant topics regarding this entity.

Deconvolution Microscopy: A Platform for Rapid On-Site Evaluation (ROSE) of Fine Needle Aspiration (FNA) Specimens that Enables Recovery of the Sample

CONTEXT

Rapid on-site evaluation (ROSE) optimizes the performance of cytology, but requires skilled handling, and smearing can make the material unavailable for some ancillary tests. There is a need to facilitate ROSE without sacrificing part of the sample.

OBJECTIVE

We evaluated the image quality of inexpensive deconvolution fluorescence microscopy for optically sectioning non-smeared FNA tissue fragments.

DESIGN

A portion of residual material from 14 FNA samples was stained for 3 minutes in Hoechst 33342 and Sypro^TM Red to label DNA and protein respectively, transferred to an imaging chamber, and imaged at 200X or 400X magnification at 1 micron intervals using a GE DeltaVision inverted fluorescence microscope. A deconvolution algorithm was applied to remove out of plane signal, and resulting images were inverted and pseudocolored to resemble an H&E section. Five cytopathologists blindly diagnosed 2 to 4 representative image stacks per case (total 70 evaluations), and later compared them to conventional epifluorescent images.

RESULTS

Accurate definitive diagnoses were rendered in 45 of 70 (64%) total evaluations; equivocal diagnoses (atypical or suspicious) were made in 21 of 70 (30%). There were two false positive and two false negative "definite" diagnoses in three cases (4/70; 6%). Cytopathologists preferred deconvolved images compared to raw images (p< 0.01). The imaged fragments were recovered and prepared into a ThinPrep or cell block without discernable alteration.

CONCLUSIONS

Deconvolution improves image quality of FNA fragments compared to epifluorescence, often allowing definitive diagnosis while enabling the ROSE material to be subsequently triaged.

EUS-FNA Biopsies to Guide Precision Medicine in Pancreatic Cancer: Results of a Pilot Study to Identify KRAS Wild-Type Tumours for Targeted Therapy

Background

Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer death and lacks effective treatment options. Diagnostic endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) biopsies represent an appealing source of material for molecular analysis to inform targeted therapy, as they are often the only available tissue for patients presenting with PDAC irrespective of disease stage. However, EUS-FNA biopsies are typically not used to screen for precision medicine studies due to concerns about low tissue yield and quality. Epidermal growth factor receptor (EGFR) inhibition has shown promise in clinical trials of unselected patients with advanced pancreatic cancer, but has not been prospectively tested in KRAS wild-type patients. Here, we examine the clinical utility of EUS-FNA biopsies for molecular screening of KRAS wild-type PDAC patients for targeted anti-EGFR therapy to assess the feasibility of this approach.

Patients and Methods

Fresh frozen EUS-FNA or surgical biopsies from PDAC patient tumours were used to screen for KRAS mutations. Eligible patients with recurrent, locally advanced, or metastatic KRAS wild-type status who had received at least one prior line of chemotherapy were enrolled in a pilot study (ACTRN12617000540314) and treated with panitumumab at 6mg/kg intravenously every 2 weeks until progression or unacceptable toxicity. The primary endpoint was 4-month progression-free survival (PFS).

Results

275 patient biopsies were screened for KRAS mutations, which were detected in 88.3% of patient samples. 8 eligible KRAS wild-type patients were enrolled onto the interventional study between November 2017 and December 2020 and treated with panitumumab. 4-month PFS was 14.3% with no objective tumour responses observed. The only grade 3/4 treatment related toxicity observed was hypomagnesaemia.

Conclusions

This study demonstrates proof-of-principle feasibility to molecularly screen patients with pancreatic cancer for targeted therapies, and confirms diagnostic EUS-FNA biopsies as a reliable source of tumour material for molecular analysis. Single agent panitumumab was safe and tolerable but led to no objective tumour responses in this population.

Performance of EUS-FNB in solid pancreatic masses: a lesson from 463 consecutive procedures and a practical nomogram

The study's main goal was the diagnostic adequacy of pancreatic endoscopic ultrasonographic (EUS) fine-needle biopsy (FNB) and associated predictive factors. The secondary objective was to define the diagnostic accuracy of EUS-FNB in the diagnosis of pancreatic masses and pancreatic malignancies. None of the studies reported the diagnostic adequacy and accuracy of EUS. We retrospectively identified patients with solid pancreatic lesions that underwent EUS-FNB between 2013, and 2018. We calculated diagnostic adequacy and related factors. Using definitive histology on the surgically resected specimen as the gold standard, we calculated diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNB. We identified a total of 463 procedures. Diagnostic specimens were adequate in 436 procedures (94.1%), while 27 biopsies provided insufficient samples (5.9%). The multivariate analysis showed that lesion size and needle caliper were the only factors influencing diagnostic adequacy. The use of a biopsy needle (OR 0.69, 95% CI 0.30-0.1.63, P 0.400) did not improve sample adequacy. We calculated sensitivity (100%), specificity (93.2%), diagnostic accuracy (93.2%), positive predictive value (97.1%), and negative predictive value (100%) using resected specimen as the gold standard. We found no significant complications. EUS-FNB is a reliable technique for the histological characterization of solid pancreatic masses.

Bronchoscopic Diagnostic Procedures Available to the Pulmonologist

In the diagnosis of lung cancer, pulmonologists have several tools at their disposal. From the tried and true convex probe endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration to robotic bronchoscopy for peripheral lesions and new technology to unblind the biopsy tools, this article elucidates and expounds on the tools currently available and being developed for lung cancer diagnosis.

Endoscopic diagnosis and management of gastric subepithelial lesions

PURPOSE OF REVIEW

The purpose of this manuscript is to provide an in-depth review of gastric subepithelial lesions (SELs) and describe the current approach to endoscopic diagnosis and management of these lesions.

RECENT FINDINGS

Gastric SELs are a relatively frequent finding on routine endoscopy (incidence 0.2-3%). A systematic approach to diagnosis and management is key because many SELs are of little consequence, while others carry a high risk of malignant transformation. Because esophagogastroduodenoscopy (EGD) cannot delineate depth of invasion or subepithelial appearance, endoscopic ultrasound (EUS) should be considered a first-line modality. Recent data suggest EUS-guided fine needle biopsy (FNB) may be superior to traditional fine needle aspiration (FNA) for the diagnosis of gastric SELs due to its ability to obtain histologic specimens for immunohistochemical staining. Alternative techniques for tissue sampling (combined with simultaneous resection) include submucosal resection, endoscopic submucosal dissection (ESD), submucosal tunnelling with endoscopic resection (STER) or endoscopic full-thickness resection (EFTR).

SUMMARY

This review details the endoscopic diagnosis and management of gastric SELs. Although EUS-guided sampling remains a first-line strategy (preferably with FNB), recent techniques including ESD, STER and EFTR have the potential to provide additional diagnostic and therapeutic options.

EUS-guided fine-needle biopsy sampling versus FNA in the diagnosis of subepithelial lesions: a large multicenter study

BACKGROUND AND AIMS

Although conventional EUS-guided FNA (EUS-FNA) has previously been considered first-line for sampling subepithelial lesions (SELs), variable accuracy has resulted in increased use of fine-needle biopsy (FNB) sampling to improve diagnostic yield. The primary aim of this study was to compare FNA versus FNB sampling for the diagnosis of SELs.

METHODS

This was a multicenter, retrospective study to evaluate the outcomes of EUS-FNA and EUS-guided FNB sampling (EUS-FNB) of SELs over a 3-year period. Demographics, lesion characteristics, sensitivity, specificity, accuracy, number of needle passes, diagnostic adequacy of rapid on-site evaluation (ROSE), cell block accuracy, and adverse events were analyzed. Subgroup analyses were performed comparing FNA versus FNB sampling by location and diagnostic yield with or without ROSE. Multivariable logistic regression was also performed.

RESULTS

Two hundred twenty-nine patients with SELs (115 FNA and 114 FNB sampling) underwent EUS-guided sampling. Mean patient age was 60.86 ± 12.84 years. Most lesions were gastric in location (75.55%) and from the fourth layer (71.18%). Cell block for FNB sampling required fewer passes to achieve conclusive diagnosis (2.94 ± 1.09 vs 3.55 ± 1.55; P = .003). The number of passes was not different for ROSE adequacy (P = .167). Immunohistochemistry was more able to be successfully performed in more FNB sampling samples (69.30% vs 40.00%; P < .001). Overall, sensitivity and accuracy were superior for FNB sampling versus FNA (79.41% vs 51.92% [P = .001] and 88.03% vs 77.19% [P = .030], respectively). On subgroup analysis, sensitivity and accuracy of FNB sampling alone was superior to FNA + ROSE (79.03% vs 46.67% [P = .001] and 87.25% vs 68.00% [P = .024], respectively). There was no significant difference in diagnostic yield of FNB sampling alone versus FNB sampling + ROSE (P > .05). Multivariate analysis showed no predictors associated with accuracy. One minor adverse event was reported in the FNA group.

CONCLUSIONS

EUS-FNB was superior to EUS-FNA in the diagnosis of SELs. EUS-FNB was also superior to EUS-FNA alone and EUS-FNA + ROSE. These results suggest EUS-FNB should be considered a first-line modality and may suggest a reduced role for ROSE in the diagnosis of SELs. However, a large randomized controlled trial is required to confirm our findings.