Endoscopic ultrasound (EUS) in staging and follow-up of patients with malt lymphoma treated conservatively

Abstract

Endoscopic ultrasonography (EUS) is an important tool for diagnosis and pretreatment staging of primary gastric lymphoma. The aim of the study was to evaluate the diagnostic importance of endosonography (EUS) in gastric lymphoma; to assess the depth of tumoral infiltration in low-grade gastric lymphoma of mucosa-associated lymphoid tissue (MALT) and to assess EUS response to medical treatment (Cyclophosphamid/Mabtera and/or anti-Helicobacter pylori therapy). 26 patients with MALT gastric lymphoma were investigated by EUS. Six of them were evaluated after the eradication of Helicobacter pylori infection and 20 after and during the cyclophosphamide/Mabtera and anti H. pylori treatment. EUS staging was compared with histopathology. Tumours were staged according to the 2000 TNM and modified Ann Arbor classification. Six patients were treated with anti - Helicobacter pylori eradication therapy. Full regression of lymphoma was observed in 2 of 6 (33.3%) patients, which was endoscopicaly and histologicaly proved. EUS correlated with histology in all (6/6). In 20 patients treated with cyclophosphamide/Mabtera therapy, EUS revealed regression of lymphoma in 14 cases. Positive correlation with histology was found in 11 patients (11/14; 78%). The initial EUS showed an increased wall thickness more than 5mm in 24 of 26 patients (92%). The thickening was predominantly of mucosa and submucosa and in 11 patients extended the muscularis propria. After the therapy, the gastric wall thickening returned to normal in 14 patients, however, 3 of them still had positive histology findings. In 2 cases, during the follow-up, the EUS showed remained thickening of gastric wall, whereas biopsies were negative. Six months later histology revealed progressive low-grade MALT lymphoma in this cases. EUS appears to be a sensitive procedure for initial staging and assessment of treatment response and long-term follow up in patients with gastric lymphoma. The importance of EUS lies in abbility to detect relapse early, too.