EUS-Guided Biopsy for Diagnosis of Lymphoma Subtype

Abstract

Background: EUS-guided fine needle aspiration (EUS-FNA) combined with flow cytometry has been shown to be effective in the diagnosis of lymphoma but not in the identification of the specific subtype of lymphoma. Core biopsies can be obtained by EUS and may enable the pathologist to identify lymphoma subtypes by preserving the histologic architecture and allowing effective immunohistochemical staining. Methods: We searched our databases from 2004 through July 2008 for consecutive patients who underwent EUS to evaluate lesions or enlarged lymph nodes in or adjacent to the GI tract and subsequently were found to have lymphoma. Procedure reports, pathology reports, and hospital charts were reviewed to collect cytologic diagnosis, flow cytometry if performed, surgical pathologic diagnosis, and final lymphoma diagnosis if not obtained by EUS. Results: 21 patients (median age: 61, men: 16, women: 45) underwent EUS-FNA, 19 of which also had core biopsy performed. Lymphoma was diagnosed in all by either EUS-FNA + FC alone (n=3, 14%), EUS-core (6, 29%), both EUS-FNA and EUS-core (8, 38%), or other non-EUS means (4, 19%). Flow cytometry was positive in 10 EUS-FNA samples. Cytologic final diagnoses included normal or nondiagnostic findings (6, 29%), suspicious for or suggestive of malignant lymphoma (11, 52%), suggestive of Hodgkin's lymphoma (2, 10%), and malignant neoplasm or lymphoma (2, 10%). EUS-core biopsy final diagnoses included Hodgkin's lymphoma (2, 11%); malignant lymphoma, large B-cell type (6, 33%); marginal zone lymphoma, B-cell type (6, 33%); suggestive of lymphoma (2, 11%), and nondiagnostic (3, 14%). The final diagnosis of lymphoma was made by EUS (all means) in 17 patients (81%). The subtype of lymphoma was determined in 15 patients (71%). Conclusions: EUS is effective in the diagnosis of suspected lymphoma. EUS-FNA with FC may make the diagnosis of B-cell lymphoma, but the addition of EUS-core allows the lymphoma subtype to be determined in 71% of patients which would provide valuable prognostic and management information to the treating physician.