INTRODUCTION: The role of endoscopic ultrasound-guided fine-needle aspiration and fine-needle biopsy (EUS-FNA/B) in the clinical management of gastrointestinal lymphoma has not been extensively studied. This study investigates the use of EUS-FNA/B in the diagnosis of first-time and recurrent gastrointestinal lymphomas at a large academic institution. MATERIALS AND METHODS: A total of 40 patients who had final diagnosis of lymphoma according to the World Health Organization (WHO) classification of tumors of hematopoietic lymphoid tissues who underwent EUS-FNA/B were included in the study. Cases with concurrent forceps mucosal biopsies or lost to clinical follow-up were excluded. The diagnostic accuracy and clinical use of EUS-FNA/B was investigated by comparing EUS-FNA/B diagnosis with the final diagnosis. RESULTS: EUS-FNA/B diagnoses were concordant with the final WHO diagnosis for as high as 72.5% of the cases. Of the remaining 27.5%, 17.5% had enough cytologic features for lymphoma diagnosis with incomplete phenotyping, while the remaining 10.0% showed features suspicious for lymphoma. Cell block and flow cytometry quality significantly affected diagnostic accuracy. Number of passes between 1 and 5 yielded better diagnostic accuracy than 6 or more passes during FNA
however, no difference was identified during procedures that used FNB alone or combined with FNA. There is no significant difference in onsite adequacy diagnostic performance of EUS-FNA performed by cytopathologists or cytotechnologists. CONCLUSIONS: EUS-FNA/B with concurrent ancillary studies such as immunocytochemistry in cell block and flow cytometry can be helpful in efficient first and recurrent diagnoses of gastrointestinal lymphomas.