Endoscopic Ultrasound Guided Fine Needle Asperation and Core Biopsy in Sampling Pancreatic Lesions

Summary: Introduction: Endoscopic ultrasound guided fine needle aspiration (EUS-FNA) has proven to be an effective method to evaluate pancreatic solid masses with high accuracy. Recently, many next-generation ultrasound biopsy needles have been introduced and used in tissue acquisition of both solid and cystic pancreatic lesions. The aim of this study was to compare the diagnostic utility and accuracy of EUS-guided core needle biopsy (EUS-CNB) with conventional EUS-FNA in evaluating pancreatic lesions. Materials and Methods: Cases of EUS-FNA and EUS-CNB performed in 2023 were retrospectively retrieved from the department's information system. Clinical information, imaging studies, and pathology reports were reviewed. EUS-FNA was performed with a 22- or 25-gauge needle via either trans-gastric or trans-duodenal approach, depending on location and texture of the suspected mass lesion in the pancreas. EUS-CNB was performed with 19- or 25-gauge biopsy needles, SharkCoreTM, or SpyBiteTM. Cytologic diagnosis was classified into non-diagnostic, benign, atypical, neoplasm, suspicious for malignant cells, and positive for malignant cells. For the study purpose, neoplasm in both cytology and biopsy included intraductal papillary mucinous neoplasm, mucinous cystic neoplasm, neuroendocrine tumor and solid pseudopapillary tumor. Applications, needle passes, and diagnostic accuracy of both methods were recorded and discussed. Results: Two hundred-fifty EUS-FNA and 80 EUS-CNB cases were retrieved in the study period. Overall diagnoses and average needle passes taken for each case were shown in Table 1. The rate of non-diagnostic was similar with both methods and atypical diagnosis was higher in EUS-CNB cases. There were 38 cases in which both EUS-FNA and EUS-CNB were preformed on the same lesion either concurrently or sequentially. The correlation of the diagnosis made on EUS-FNA and EUS-CNB was illustrated in Table 2. Among 12 cases of cystic lesion, the diagnosis made on EUS-CNB included 2 non-diagnostic, 3 benign, 2 serous cyst, and 5 mucinous cyst (IPMN); the diagnosis made on EUS-FNA was 1 non-diagnostic, 4 benign, 2 atypical, and 1 suspicious for malignancy. For 26 solid pancreatic masses, the diagnosis made on EUS-CNB was 3 benign, 6 atypical, 3 neoplasm, 1 suspicious and 13 malignant; the diagnosis made on EUS-FNA was 5 benign, 3 neoplasm, 2 suspicious and 16 malignant. Conclusions: Both EUS-FNA and EUS-CNB were excellent methods in making a diagnosis on pancreatic lesions. EUS-CNB may provide a more precise diagnosis for pancreatic cystic lesion, while EUS-FNA may be compatible or better in targeting deep seated solid pancreatic lesions.