Analysis of malignant biology and gene disorder in gastric MALT lymphomas

随着低度恶性粘膜相关淋巴组织B细胞淋巴瘤(MALT)新实体的建立，对胃淋巴瘤进行了重新评估，并对MALT淋巴瘤的最佳治疗方案进行了展望。连续40例胃B细胞淋巴瘤手术病例经病理组织学分型为MALT淋巴瘤(26例，低度恶性18例，高度恶性8例)和非MALT淋巴瘤(14例)，分析其临床病理及预后，并进行比较研究。与非MALT淋巴瘤相比，MALT淋巴瘤患者往往没有症状或症状模糊，且病程较长，术后预后较好，无论有无高级别转化、淋巴结转移或术后化疗。直到组织学检查，MALT淋巴瘤的范围更大，粘膜和粘膜下层的浅表扩散，以及肿瘤的边缘回避。MALT淋巴瘤患者的5年生存率为94%，显著高于非MALT淋巴瘤患者的59%。而%的高级别MALT淋巴瘤与59%的非MALT淋巴瘤之间差异无统计学意义。胃MALT淋巴瘤在生物学上不同于传统的非MALT淋巴瘤，是目前最理想的全胃切除加2级淋巴结清扫的手术方式。最近对幽门螺杆菌感染引起的MALT淋巴瘤的发病机制进行了新的研究，因此，未来的治疗方案将进行临床过渡。

Since new entity of low-grade B-cell lymphoma of mucosa associated lymphoid tissue (MALT) was established, re-evaluation of gastric lymphoma was carried on and optimal treatment protocol of MALT lymphoma has been anticipated. Consecutive 40 surgical cases of gastric B-cell lymphoma were histopathologically reclassified as MALT lymphoma (n=26 ; 18 low-grade and 8 high-grade) and non-MALT lymphoma (n=14), analyzed clinicopathologically including prognosis, and comparatively investigated between two groups. Compared to non-MALT lymphomas, patients of MALT lymphoma often presented no symptoms or vague symptoms with longer history and better prognosis after surgery irrespective of high-grade transformation, lymph node involvement or postoperative chemotherapy. MALT lymphomas exhibited larger extent, superficial spread of the mucosa and submucosa, and evasive margins of the tumor until scrutinized histology. 5-yr survival rate of patients with MALT lymphoma was 94%, significantly higher than 59% of non-MALT lymphoma. However, no significant difference was obtained between 64% of high-grade MALT lymphoma and 59% of non-MALT lymphoma. Gastric MALT lymphomas should be biologically different from conventional non-MALT lymphomas, leading to the optimal surgical treatment of total gastrectomy with level 2 lymph node dissection so far. Newly investigated pathogenesis of MALT lymphoma by Helicobacter Pylori infection would consequently take the clinical transitions of treatment protocol in the future.