摘要目的：探讨琥珀酸脱氢酶缺陷型胃肠道间质瘤（ GIST）的临床病理学特征、诊断、鉴别诊断及独立分型意义。方法对120例胃GIST行免疫组织化学方法检测SDHB和SDHA蛋白表达，同时所有病例均进行CD117、DOG－1、CD34、平滑肌肌动蛋白（ SMA）、结蛋白、S－100蛋白、细胞角蛋白（CK）、Ki－67的免疫组织化学染色（EnVision法）。部分病例还进行CKIT基因第9、11、13、17号外显子及血小板源生长因子受体（ PDGFRA ）基因第12和18号外显子的基因检测。结果发现8例（6．6％）琥珀酸脱氢酶缺陷型GIST病例，患者年龄16～65岁（平均36．2岁），男∶女＝3∶5，累及胃窦6例、小弯1例、胃底1例。大体检查肿瘤呈多结节状或分叶状，大小3～10 cm；显微镜下瘤细胞以上皮样细胞为主，部分可混杂梭形细胞结节，其中5例可见脉管内瘤栓。免疫组织化学8例中SDHB皆阴性，SDHA有5例阴性。其他标志物CD117、DOG－1、CD34均阳性表达， SMA、结蛋白、S－100蛋白、CK皆阴性。8例基因突变检测CKIT和PDGFRA均为野生型。7例患者获得随访结果，随访时间为2～60个月（平均23．3个月），皆生存。其中3例在诊断时即出现肝脏多发性转移，1例在随访17个月中出现网膜及肠系膜多发性病灶，患者带瘤生存。结论琥珀酸脱氢酶缺陷型GIST是一种特殊亚型的GIST，多累及儿童和青年人，女性多见，以多结节状生长方式，上皮样瘤细胞为主，常见脉管内瘤栓、常发生淋巴结及肝脏转移，生物学行为惰性特征。免疫组织化学SDHB检测有助于将之从普通型GIST中检出。

abstractsObjective To study the clinicopathologic features , diagnosis and differential diagnosis of succinate dehydrogenase ( SDH ) deficient gastrointestinal stromal tumors ( GISTs ) as a unique tumor subtype.Methods SDHB and SDHA immunohistochemistry was performed in 120 gastric GISTs, in addition to CD117, DOG-1, CD34, smooth muscle actin (SMA), desmin,S-100 protein, cytokeratin (CK) and Ki-67.Subset of the cases was further evaluated for the presence of mutations in CKIT exons 9, 11, 13 and 17 mutations and platelet derived growth factor receptor alpha ( PDGFRA) exons 12 and 18.Results Eight of 120 (6.6%) GIST cases were found SDH-deficient including 3 male and 5 female patients (median age of 36.2 years;ranging 16 to 65 years of age).The tumors involved antrum (6 cases), lesser curvature (1 case) and fundus (1 case).Macroscopically, the dominant tumor masses varied from 3 to 10 cm in diameter with a multinodular or plexiform pattern involving the gastric wall .Microscopically ,tumor cells had predominantly epithelioid morphology , with occasional mixed spindle cell nodules .Lymphovascular invasion was identified in 5 cases.Immunohistochemistry for SDHB was negative in all 8 cases, and SDHA was negative in 5 cases.All 8 SDHB negative cases also expressed CD 117, DOG-1 and CD34, but were negative for SMA, desmin, S-100 and CK.All 8 cases were found to have wild-type CKIT and PDGFRA genes. Available clinical follow-up were obtained in 7 cases, ranging from 2 to 60 months ( median follow-up 23.3 months) , and all patient were alive .Three cases were found to have liver metastases at their first diagnosis , and one developed omental and mesenteric metastases in 17 months.Conclusions SDH-deficient GIST is a distinct subtype of GIST , with a predilection to occur in young and female patients .Characteristic pathological findings include multinodular gastric wall involvement , epithelioid cell morphology , frequently lymphovascular invasion with occasional lymph node and liver metastases , but an overall indolent clinical behavior.Immunohistochemistry for SDHB is required for the diagnosis .