S2484 Endoscopic Ultrasound With Fine Needle Aspiration for Diagnosis of Pancreatic Tumors in Patients With Benign Magnetic Resonance Imaging: Single Center Case Series

Abstract

Introduction: Pancreatic cancer is the fourth leading cause of cancer-related death in the United States. Computed tomography (CT) scan and Magnetic resonance imaging (MRI) are used for early detection of small pancreatic lesions and cancer risk stratification. Endoscopic ultrasonography (EUS) with FNA (Fine Needle Aspiration) provides accurate diagnosis of pancreatic tumors. This case series introduces four cases of pancreatic tumors diagnosed using EUS/FNA that have been missed on MRI studies Case Description/Methods: Case 1 64-year-old male was referred for evaluation of pancreatic duct dilation on MRI with no detected mass. EUS revealed 15mm x 15mm mass of pancreas. FNA was performed and pathology was consistent with adenocarcinoma Case 2 55-year-old female was referred for evaluation of pancreatic cystic lesion found on MRI with no worrisome features. EUS revealed 15mm x 15mm pancreatic lesion. FNA was performed and pathology was consistent with pancreatic neuroendocrine tumor. Case 3 82-year-old female was referred for evaluation of pancreatic duct dilation on MRI with no discrete mass identified. EUS revealed 26mm x 27mm pancreatic lesion. FNA was performed and pathology was consistent with invasive adenocarcinoma. Case 4 62-year-old male was referred for evaluation of pancreatic lesion on MRI abdomen with features consistent with lipoma. EUS revealed 15mm x 13mm pancreatic lesion. FNA was performed and pathology was consistent with adenocarcinoma. Discussion: The diagnosis of pancreatic neoplasms relies heavily on identification of lesions on CT and MRI. While the sensitivity of MRI is similar to that of CT, the former is preferred in patients with high pre-test probability of pancreatic neoplasms. Sensitivity of EUS has been shown to be significantly higher in detecting pancreatic tumors when compared to CT, However, studies evaluating EUS to MRI are scarce. This case series presents four patients in whom pancreatic tumors were missed on MRI. Two patients had no radiologic evidence of a tumor, while the other two demonstrated lesions with no malignant features. EUS has the added benefit of tumor sampling and higher sensitivity in detecting pancreatic lesions. This case series highlights the potential limitations in the use of MR imaging in diagnosis of pancreatic cancers. Some evidence suggests that EUS is more sensitive than MRI and CT in detecting pancreatic lesions. However, the cost effectiveness and risks associated with routine EUS in the detection of pancreatic lesions has not been evaluated.Figure 1.: (A): Case 3 EUS with arrow pointing at 26mm x 27mm pancreatic lesion (B): Case 4 EUS with arrow pointing at 15mm x 13mm pancreatic lesion.