胃丛状血管黏液样肌纤维母细胞瘤2例临床病理观察

目的探讨胃丛状血管黏液样肌纤维母细胞肿瘤(PAMT)的临床病理学特征及诊断、鉴别诊断要点。方法对2例胃丛状血管黏液样肌纤维母细胞肿瘤进行临床病理、免疫组化和电镜研究。结果临床表现为无症状或上腹部不适、疼痛。胃镜示肿物向胃腔内突出。镜下肿瘤在胃壁之间呈结节状、丛状生长,与胃壁平滑肌交错排列,肿瘤富于小的薄壁血管,细胞间富含黏液样或纤维黏液样基质;瘤细胞核呈梭形或卵圆形,核仁不明显,胞质轻度嗜酸性,细胞异型性不明显。免疫组化示肿瘤细胞SMA、MSA和h-caldesmon(+),个别细胞PR(+),CD117、CD34和S-100(-)。电镜示肿瘤有肌纤维母细胞分化。结论胃丛状血管黏液样肌纤维母细胞肿瘤是罕见的肿瘤,具有独特的形态特征,其诊断和鉴别诊断主要依靠病理组织学和免疫组化。

Plexiform angiomyxoid myofibroblastic tumor:a clinicopathological study

Objective To explore the clinicopatholgic features and differential diagnosis of gastric plexiform angiomyxoid myofibroblastic tumor(PAMT).Methods Two cases of gastric PAMT were studied with conventional histopathological,immunohistochemical stains and electronic microscopy.Results The clinical symptoms of gastric PAMT included stomachache and heartburn,or without any gastric symptom.The tumors were located at the antrum in the two cases,and grossly,the tumor was whitish to brownish or reddish,and formed a submucosal or transmural mass.Microscopically,the tumor was characterized by a plexiform growth pattern,the proliferation of cytologically bland spindle cells,and a myxoid stroma with small vessels that was positive for Alcian blue stain.Immunohistochemically,the tumor cells were positive for smooth muscle actin and negative for CD117 and CD34.Conclusions Gastric PAMT is a rare neoplasm.The diagnosis of PAMT mainly relies on histopathological and immunochemical findings.Differential diagnoses include gastrointestinal stromal tumor and other mesenchymal tumors of the gastrointestinal tract.