Diagnostic value of endoscopic ultrasonography combined with detection of immunoglobulin and T-cell receptor gene rearrangements in primary gastrointestinal lymphoma

Abstract

Objective To evaluate the diagnostic value of endoscopic ultrasonography (EUS) combined with detection of immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements in primary gastrointestinal lymphoma (PGIL). Methods From 12nd January, 2012 to 23rd May, 2014, the clinical data of 24 patients with suspicious PGIL under endoscopy (regular biopsy negative and without treatment) and underwent further EUS examination was retrospectively analyzed. All patients received EUS-guided biopsy or EUS-guided fine needle aspiration (FNA) and the tissue specimens were detected for Ig and TCR gene rearrangements. Considering biopsy result, surgical pathological diagnosis and follow-up result as gold standard, the clinical significance of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of EUS combined with Ig/TCR gene rearrangements in PGIL were explored. Results Among 24 patients, 19 patients were finally diagnosed as PGIL, which were all non-Hodgkin's lymphoma (NHL); monoclonal gene rearrangement was found in 13 cases of the 19 cases. The left five cases were not lymphoma lesions (three cases of gastritis, one case of leather stomach and one case of malignant melanoma) with no monoclonal gene rearrangement. In cases diagnosed as PGIL, 14 were B cell NHL, which included eight cases of muscosa-associated lymphoid tissue (MALT) lymphoma and six cases of diffuse large B cell lymphoma. Of which, immunoglobulin heavy chain (IgH)/immunoglobulin kappa (IgK) gene rearrangement was found in 11 cases. A total of five cases were T cell NHL including one case of anaplastic large cell lymphoma, one case of NK/T cell lymphoma and three cases of enteropathy-associated T-cell lymphomas. TCR gene rearrangement was found in two cases. Because theoretically, there was no gene rearrangement in natural killer (NK)/T cell lymphoma, so NK/T cell lymphoma was excluded from statistical analysis. The sensitivity, specificity, PPV, NPV and accuracy of EUS combined with Ig/TCR gene rearrangements detection in PGIL were 72.2%, 100.0%, 100.0%, 50.0% and 78.3%, respectively. Conclusion The detection of monoclonal gene rearrangement in tissues from EUS-guided biopsy or EUS-guided FNA had better diagnostic value in PGIL, which improved the objectivity and accuracy of lymphoma diagnosis. Key words: Gastrointestinal neoplasms; Lymphoma; Gene rearrangement; Endoscopy