Endoscopic Ultrasound-Guided Fine-Needle Aspiration and Biopsy in the Diagnosis of Pancreatic Neuroendocrine Neoplasms: A Series of 72 Cases

Background

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) are widely used for the diagnosis of pancreatic tumors. The aim of our study was to compare the diagnostic performance of EUS-FNA and EUS-FNB for the diagnosis of pancreatic neuroendocrine (NE) neoplasms and to review tumors' cytopathology.

Methods

Patients who underwent EUS-FNA and EUS-FNB for pancreatic NE neoplasms were reviewed retrospectively. Sample adequacy, diagnostic yield (defined as percentage of definitive diagnosis) and sensitivity were compared between FNA and FNB. The common cytologic features of pancreatic NE neoplasms were reviewed and quantified.

Results

A total of 72 patients were diagnosed with pancreatic NE neoplasms at our institution by EUS-FNA and EUS-FNB. The mean age at diagnosis was 57.5 years. The proportions of adequate samples were 68/68 (100%) for EUS-FNA and 57/58 (98.3%) for EUS-FNB. EUS-FNB demonstrated a higher diagnostic yield than FNA, 57/58 (98.3%) for EUS-FNB and 61/68 (89.7%) for EUS-FNA. When concurrent EUS-FNBs were performed, the diagnostic yield increased to 97.1% with an incremental increase of 5/68 (7.4%) relative to EUS-FNA alone. When sensitivity was defined as the ability to identify cytological atypia and above categories, the sensitivity for EUS-FNA and EUS-FNB was 98.5% and 91.4%, respectively. The grading of well-differentiated neuroendocrine tumors was 32/51 Grade 1 tumors (62.7%) and 19/51 Grade 2 tumors (37.3%). Four patients were found to have poorly differentiated neuroendocrine carcinomas.

Conclusion

EUS-FNA and EUS-FNB were comparable in sample adequacy for diagnosing pancreatic NE neoplasms. EUS-FNA appeared to have higher sensitivity but lower diagnostic yield than EUS-FNB in our study.