Endoscopic Ultrasound-Guided Fine Needle Aspiration Cytology of Gastrointestinal Tract Tumors and Related Organs: Predictive Factors for Accurate Cytopathological Diagnosis

Abstract

Background: Endoscopic ultrasonography (EUS) is well-established, highly accurate clinical diagnostic test for detection and staging of gastrointestinal tract lesions and related organs. The addition of endoscopic guided fine needle aspiration cytology (EUS-FNAC) has improved the performance characteristics of EUS. Aim: Evaluate the validity of EUS-FNAC in diagnosis of gastrointestinal tract lesions and related organs and assess predictive factors for an accurate EUS-FNAC diagnosis. Methods: Our study included cytological sampling from one hundred sixty-six lesions obtained from gastrointestinal tract and related organs. Factors affecting EUS-FNA accuracy were analyzed. The histopathological results or clinical follow-up were used as the gold standard method. Results: Samples were obtained from: pancreatic masses (n = 80), gastric masses (n = 34), lymph nodes (n = 22), hepatobiliary masses (n = 18) and rectal masses (n = 2). Statistical analysis of sensitivity, specificity, Positive Predictive Value, Negative Predictive Value, and diagnostic accuracy of EUS alone was 80.4%, 51.6%, 75.8%, 76.2% and 75.9% respectively. The sensitivity, specificity, positive predictive value and negative predictive value of EUS-FNAC are 78.8%, 96.8%, 97.6% and 73.2% respectively. Addition of FNAC to EUS improved diagnostic accuracy to 85.5%. Positive statistical association was present between cytological adequacy and adequate cell block preparations, larger lesion size, presence of rapid on site evaluation (ROSE) and obtaining at least two passes from target lesion. Conclusions: EUS is valuable diagnostic and cost effective tool for gastrointestinal tract lesions and related organs when combined with FNAC.