Role of repeated endoscopic ultrasound-guided fine needle aspiration in small solid pancreatic masses with previous indeterminate and negative cytological findings.

INTRODUCTION

Despite advances in imaging techniques, the differentiation between pancreatic cancer and benign lesions remains difficult. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is an effective method for providing tissue diagnosis, but problems occur when lesions are small or the cytological diagnosis is indeterminate.

AIM

To prospectively evaluate the utility of EUS-FNA in patients with small solid pancreatic lesions and those with initial indeterminate or negative cytological diagnosis.

METHODS

During the study period we performed a total of 119 EUS-FNA procedures on 46 patients (mean age 56.3 years) for 47 small solid pancreatic lesions (range 7-30 mm, mean 17.2 mm in diameter). FNAs were performed in the presence of a cytopathologist. If cytological diagnoses were indeterminate, EUS-FNA was repeated within 3 weeks. Diagnoses were confirmed histologically or by follow-up (clinical and imaging: EUS +/- FNA and CT).

RESULTS

Localization of the lesions: head 28 (60%), uncinate process 4 (9%), body 11 (23%) and tail 4 (9%). On average, 3.7 passes were performed. We observed no complications. Initial cytological findings were: malignant 17 (36%), benign 21 (45%), and indeterminate 9 (19%). 8 (78%) of the indeterminate findings were confirmed to be malignant on repeated procedures. A diagnosis of pancreatic cancer was subsequently confirmed in 1 patient who had a benign cytological finding. 19 patients underwent surgery. Histology confirmed a neoplasm in all cases. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 68, 100, 100, 73 and 83%, respectively. After repeated EUS-FNAs of indeterminate findings sensitivity, negative predictive value and diagnostic accuracy rose to 92, 77 and 96%, respectively.

CONCLUSION

EUS-FNA is a highly effective method for providing tissue diagnosis in patients with small solid pancreatic masses. Repeated procedures enhanced diagnostic accuracy in indeterminate findings, among which was high percentage of malignancies. EUS-FNA reduced the number of operations in patients with pancreatic solid masses.