Tu1672 Final Cytopathologic Diagnosis of Initially “Indeterminate” Pancreatic Mass Lesions

Abstract

Tu1672 Final Cytopathologic Diagnosis of Initially “Indeterminate” Pancreatic Mass Lesions Nigeen F. Hessami, Stuart R. Gordon, Timothy B. Gardner* Gastroenterology and Hepatology, Dartmouth-Hitchcock Medical Center, Lebanon, NH Background & Aims: Endoscopic Ultrasound (EUS)-guided Fine Needle Aspiration (FNA) of pancreatic masses is generally very accurate; occassionally however, cytology is classified as atypical or suspicious. These “indeterminate” results often lead to repeat procedures along with patient and provider uneasiness. We aimed to determine the final pathologic diagnosis in patients with pancreatic masses undergoing EUS-FNA whose initial cytology report was characterized as “atypical” or “suspicious”. Methods: A retrospective chart review was performed on patients referred for EUS-FNA of a pancreatic mass at our medical center from 2000-11. Initial cytology results were characterized as “benign”, “atypical”, “suspicious”, or ”malignant”. Reports were then compared to the final pathology of the pancreatic mass which was obtained from a repeat EUS-FNA or a subsequent surgical specimen. The following lesions were considered malignant: lymphoma, adenocarcinoma, islet cell tumor, and metastatic disease. Results: 619 patients met the inclusion criteria. On initial EUS-FNA, 448 had a “malignant” cytology, 26 had “suspicious” cytology, 29 were “atypical”, and 88 were “benign”. Of the 26 with “suspicious” cytology, 92.3% eventually were found to have a malignant diagnosis. In the 29 patients with “atypical” cytology, 65.5% eventually were eventually deemed malignant. In the 448 patients with an initial “malignant” report, 99.3% had the malignancy subsequently confirmed. The probability of an initial “suspicious” diagnosis being negative and an initial “malignant” diagnosis being negative were equivalent (pZ0.23). Linear regression demonstrated that a “suspicious” cytology was most likely in lesions from the neck (OR Z 2.01, 95% CI 1.23-2.79) and body (OR Z 2.23, 95% CI 1.78-2.67) and “atypical” cytology from the uncinate (OR Z 3.05, 95% CI 2.47-3.64). Conclusion: EUS-FNA of pancreas masses with an initial “suspicious” cytology are almost always found eventually to be malignant. These findings suggest that “suspicious” cytology may be treated as if the result were malignant. Probability that a Pancreatic Mass was Malignant given the EUSguided FNA Cytology Results