胃丛状血管黏液样肌纤维母细胞瘤临床病理特点与预后分析

目的:回顾性分析胃丛状血管黏液样肌纤维母细胞瘤（PAMT）的临床病理特点、诊断及预后。方法:对4例PAMT的临床资料、组织学特点、免疫组化、特殊染色及基因突变进行分析,并结合相关文献讨论。结果:临床症状包括恶心、呕吐、体重减轻、胃部肿块或幽门梗阻。胃镜示黏膜下隆起性肿物,好发于胃窦部。光镜下肿瘤组织呈特征性的丛状或结节状生长于黏膜下胃壁肌层内，结节呈黏液样，大小和形状不一，结节内有增生的肌纤维母细胞和小血管，细胞异型性不明显，核分裂象罕见。4例均有SMA（+），Vimentin（+），Ki-67（1%~3%），其中有2例出现h-caldesmon（弱+）。阿尔辛蓝染色显示细胞间黏液样基质。KIT和PDGFRA突变位点分析显示4例均未出现突变。4例患者均行远端胃切除，术后未见复发转移。结论:PAMT是一种罕见的间叶组织肿瘤，具备良性的生物学行为。

Plexiform angiomyxoid myofibroblastic tumor:Correlation to clinicopathological features and prognosis

Objective:To analyze the clinicopathological features and differential diagnosis,therapeutics and prognosis in patients with plexiform angiomyxoid myofibroblastic tumor.Methods:Four cases of PAMT fusions were analyzed by clinical data and histology,immunohistochemistry，special stain,gene mutation,followed by discussion through review the relevant literature．Results:Clinical symptoms include nausea,vomiting,weight loss,gastric mass or pyloric obstruction.The tumors were located at the antrum,and formed a submucosa.Microscopically,the tumor was characterized by a plexiform growth pattern,mucinous nodules had different sizes and shapes.There were many fibroblasts and small blood vessels in the nodules.The tumor cells atypia was not obvious,nuclear fission was rare.SMA and Vimentin were positive in tumor of four patients,and low expression of Ki-67,h-caldesmon were positive in two patients.The intercellular myxoid matrix was tested by alcian blue staining.The four patients did not have mutations in either of KIT and PDGFRA.Conclusion:PAMT is a rare mesenchymal tumor of the stomach,with benign biological behaviour.