Aims:
Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) as a method of obtaining
preoperative diagnosis of pancreatic neuroendocrine tumours (PNETs) has been reported
in several series. Fine needle biopsies (FNB) are increasingly employed to obtain
core specimens during EUS. However, the differences in efficacy between these sampling
methods in the diagnosis of PNETs still needs to be defined.
Methods:
Over a 12-year period, all patients who underwent EUS-guided tissue sampling of suspicious
pancreatic lesions identified by pancreatic protocol CT or MRI, with clinical, endoscopic
and pathologic details were entered into an electronicdatabase. Lesions underwent
EUS-FNA or FNB sampling, or a combination of the two, if feasible. The accuracy and
safety of different EUS guided sampling methods for confirmed PNETs were investigated.
Results:
A total of 91 patients (M/F: 42/49, median age: 57 years, range: 26 – 87 years), who
underwent a 102 EUS procedures, had a final diagnosis of PNET confirmed by histopathological
examination as well as multidisciplinary review and clinical follow up. Preoperatively,
both EUS-guided sampling modalities were used in 28 procedures, EUS-FNA alone was
used in 61 cases, while EUS-FNB alone in 13 cases. The diagnostic yield of EUS-FNA
and EUS-FNB alone, including the inadequate specimens, was 77.5% (95% CI: 68.9 – 86.2%)
and 85.4% (95% CI: 74.6 – 96.2%), respectively. The combination of both sampling modalities
established the diagnosis in 96.4% (95% CI: 89.6 – 100%) of cases (27/28), and was
significantly superior to EUS-FNA alone. The diagnostic accuracy among the adequate
samples for EUS-FNA, EUS-FNB and for the combination of the two methodswere 88.4%
(95% CI: 80.9 – 96.0%), 94.3% (95% CI: 86.6 – 100%) and 100% (95% CI: 100 – 100%).
There was one reported complication, a post-FNA bleeding, treated conservatively.
Conclusions:
EUS-FNB improves the diagnostic accuracy and confers additional information to cytological
assessment of PNETs.
