Oncogenesis and clinicopathologic characteristics of MALT lymphoma

AP 12-MALT 1融合基因是粘膜相关淋巴组织（MALT）淋巴瘤的特异性基因。我们最近描述了一种多重RT-PCR检测这种裂变基因，可以适用于石蜡切片。利用该分析，我们阐明了肺、皮肤、眼附属器、结肠和胃MALT淋巴瘤的临床病理学意义。41%的肺MALT淋巴瘤中存在融合基因。融合基因阳性肿瘤患者很少有自身免疫性疾病，其LDH水平通常正常。在组织学上，融合阳性肿瘤是典型的MALT淋巴瘤，并且与核BCL 10表达相关（Am J Pathol，2003）。24例亚洲皮肤MALT淋巴瘤患者的API 2-MALT 1融合和疏螺旋体感染均为阴性。然而，与融合基因密切相关的核BCL 10表达在肿瘤细胞中频繁检测到，并且与肉眼可见的结节性病变相关（Am J Surg Pathol，2003）。麦芽莱姆 关于我们 眼附属器的肉瘤在13%的分析病例中显示API 2-MALT 1融合。这些阳性病例通常显示其他染色体异常，提示某些融合阳性眼MALT淋巴瘤病例可能进展为高级别淋巴瘤（Mod Pathol，2003）。结肠MALT淋巴瘤在15%的分析病例中显示出API 2-MALT 1融合。该融合基因多见于男性患者，且与临床分期相关。后一项观察结果表明，可能需要对融合阳性的结肠MALT淋巴瘤进行密切随访（Mod Pathol，2003）。对累及多器官的胃MALT淋巴瘤的分析表明，这些病例多为API 2-MALT 1融合阳性，H. pylon感染，对H.幽门螺杆菌根除治疗（J Gastroenterol，2004）。对胃MALT淋巴瘤的大规模分析显示，API 2-MALT 1融合阳性肿瘤对H.幽门螺杆菌根除治疗。因此，我们将胃MALT淋巴瘤分为三组：（A）根除敏感，（B）根除抵抗，融合基因阴性，和（C）根除抵抗，融合基因阳性。各组均表现出独特的临床病理学特征（Am J Surg Pathol，2004）。报告了一例HIV阴性年轻男性发生的API 2-MALT 1融合阴性肺MALT淋巴瘤病例（勒克Lymphoma，2004）。少

AP12-MALT1 fusion gene is specific to mucosa-associated lymphoid tissue (MALT) lymphoma. We recently described a multiplex RT-PCR assay for this fission gene that can be applicable to paraffin sections. Using this assay, we clarified clinicopathological significances in MALT lymphomas of the lung, skin, ocular adnexa, colon, and stomach. The fusion gene was detected in 41% of pulmonary MALT lymphoma cases. The patients with fusion gene-positive tumors rarely had autoimmune disease, and their LDH level was often normal. Histologically the fusion-positive tumors were typical for MALT lymphoma, and were associated with nuclear BCL10 expression (Am J Pathol, 2003). Twenty-four Asian cases of cutaneous MALT lymphomas were negative for API2-MALT1 fusion and Borrelia infection. However, nuclear BCL10 expression, which is closely associated with the fusion gene, was frequently detected in the tumor calls, and was associated with macroscopically nodular lesion (Am J Surg Pathol, 2003). MALT lym … More phoma of the ocular adnexa showed the API2-MALT1 fusion in 13% of the cases analyzed. These positive cases often showed other chromosomal abnormalities, suggesting that some cases of the fusion-positive ocular MALT lymphoma might progress to high-grade lymphoma (Mod Pathol, 2003). MALT lymphoma of the colon showed the API2-MALT1 fusion in 15% of the cases analyzed. The fusion gene was often found in male patients, and was associated with advanced clinical stage. The latter observation suggests that a close follow-up may be needed for fusion-positive MALT lymphomas of the colon (Mod Pathol, 2003). An analysis of gastric MALT lymphomas involving multiple organs showed that these cases were frequently positive for API2-MALT1 fusion, negative for H. pylon infection, and resistant to H. pylori eradication therapy (J Gastroenterol, 2004). A large-scale analysis of gastric MALT lymphoma showed that API2-MALT1 fusion-positive tumors were totally resistant to H. pylori eradication therapy. Consequently, we divided gastric MALT lymphomas into three groups: (A) eradication-sensitive, (B) eradication-resistant, fusion gene-negative, and (C) eradication-resistant, fusion gene-positive. Each group showed unique clinicopathological features (Am J Surg Pathol, 2004). An API2-MALT1 fusion-negative pulmonary MALT lymphoma case which was developed in a HIV negative young man was reported (Leuk Lymphoma, 2004). Less