Finding a needle in a haystack: Endoscopic ultrasound-guided fine-needle aspiration for solid pancreatic masses in the setting of chronic pancreatitis.

BACKGROUND

The mainstay for the definitive diagnosis of pancreatic lesions is endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). However, there is evidence that EUS-FNA has low sensitivity in the setting of chronic pancreatitis (CP). This single-center retrospective study aimed to compare and analyze the diagnostic yield of EUS-FNA for solid pancreatic lesions in the presence and absence of CP, and to further investigate strategies for overcoming the low diagnostic yield in the setting of CP.

METHODS

This study identified patients who underwent EUS-FNA at Sanford USD Medical Center (SD, USA) for a solid pancreatic lesion between July 15, 2011, and November 30, 2017. Data on demographics, clinical features, cross-sectional imaging findings, EUS findings, cytology/pathology, and clinical follow up were collected.

RESULTS

The final diagnosis was adenocarcinoma in 156 patients (67%), neuroendocrine tumor in 27 (12%), lymphoma in 6 (3%), metastatic malignancy in 8 (4%), and benign etiologies in 35 (15%). CP was identified in 44/234 (19%) patients. The overall diagnostic sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for EUS-FNA were 92.9%, 97.1%, 99.5%, 70.8%, and 93.5%, respectively. The sensitivity (80% vs. 95%, P=0.020) and accuracy (86% vs. 95%, P=0.043) were significantly lower in patients with CP compared to those without CP.

CONCLUSION

CP can significantly affect the EUS-FNA diagnostic yield of solid pancreatic neoplasms. A high index of clinical suspicion is required in these cases to make a definitive diagnosis.