The Diagnostic Accuracy of Endoscopic Ultrasound-Guided Fine Needle Aspiration in Patients with Endoscopic Biopsy Negative Upper Gastrointestinal Lesions

Objective To determine the diagnostic accuracy of endoscopic ultrasound guided (EUS) fine needle aspiration in patients who had inconclusive endoscopic biopsies of the same lesion Methodology This retrospective study was conducted at Pak Emirates Military Hospital, Rawalpindi, Pakistan from Jan 2018 to July 2020. Patients who underwent EUS guided FNAC from June 2017 to July 2020 were screened. The FNAC results of patients satisfying the inclusion ciritera were compared with either a surgical biopsy in patients in whom surgeries were done, while in the remaining patients, EUS FNAC results were compared with a 3 months radiological and/or 6 months clinical follow-up. The final diagnosis was defined based on the following criteria: (1) Malignant lesions (n=36), histopathologic diagnosis obtained based on surgery resected samples (n=18) or clinical diagnosis as neoplasm based on clinical follow-up of symptoms (n=30) or radiologic diagnosis based on imaging follow-up at 3 months (n=13) (2) Benign lesions (n=18), benign cytopathologic histopathologic findings and clinical follow-up with no evidence of malignant progression or metastasis. Results EUS-guided FNA cytology turned out to be malignant in 60 percent (n=36) of the specimens. 30 percent of the samples showed benign epithelial cytology ( n=18) while in 10 percent  of the cases (n=6), the tissue samples were deemed insufficient for cytological diagnosis. The accuracy came out to be 66.6 percent (n=10 were true negative), sensitivity 93.4 percent, and specificity 100 percent.  Conclusion EUS guided-FNA cytology of the sub-mucosal upper GI lesions is highly sensitive and specific for upper GI lesions, which are negative on endoscopic biopsies.