EUS FNB Versus FNA With On-Site Cytopathology in Solid Pancreatic Masses

Endoscopic ultrasound (EUS) guided fine needle aspiration (EUS-FNA) is the primary technique
for tissue acquisition for pancreatic lesions. Despite widespread adoption of the techniques,
the diagnostic yield of EUS-FNA for pancreatic lesion is highly variable, with sensitivities
ranging from 64-95%, specificities ranging from 75-100% and overall diagnostic accuracy
ranging from 78-95%.

Despite its mainstay as the primary technique for tissue acquisition, EUS-FNA has several
limitations. The standard EUS-FNA does not routinely provide core biopsy specimen with
preserved tissue architecture, which is required for immunohistochemical staining and for
definitive diagnosis of conditions, such as lymphoma, gastrointestinal stromal tumors,
Immunoglobulin G (IgG)-4-associated lymphoplasmacytic sclerosing pancreatitis. Furthermore,
the diagnostic yield of EUS-FNA is highly dependent on the availability of bedside
cytotechnologist or cytopathologist for rapid onsite evaluation (ROSE), which increases the
overall cost required to perform EUS-FNA.

Recently, multiple dedicated EUS fine needle biopsy (FNB) needles have been developed to
obtain core specimens. Early small studies have shown promising results with these EUS-FNB
needles.

The objective of this paired cohort study is to evaluate the diagnostic accuracy of EUS-FNA
with ROSE compared to EUS-FNA with ROSE. If EUS-FNB without ROSE is shown to be non-inferior
to the current standard of care of EUS-FNA with ROSE in pancreatic lesions, this study has
the potential to make EUS-guided tissue acquisition more economical (with elimination for the
need for cytopathology staff onsite) as well as provide core histological specimen without
sacrificing the overall diagnostic yield.

Inclusion Criteria:

- Patient ≥ 18 years of age referred for EUS-guided biopsy for pancreatic mass lesions

Exclusion Criteria:

- Refusal to consent form

- Uncorrectable coagulopathy (INR > 1.5)

- Uncorrectable thrombocytopenia (platelet < 50,000)

- Uncooperative patients

- Pregnant women (women of childbearing age will undergo urine pregnancy testing, which
is routine for all endoscopic procedures)

- Medically unstable for sedation

- Entirely cystic lesions

- Lesions inaccessible to EUS