消化道及腹腔软组织平滑肌肿瘤的临床病理和免疫组化特点

目的探讨消化道和腹腔软组织平滑肌肿瘤临床病理和免疫组化特点。方法对17例消化道及腹腔软组织平滑肌肿瘤进行临床病理、免疫组化观察,并对7例患者进行随访。结果男性7例,女性10例;年龄23~63岁,平均49岁。肿瘤位于胃肠道8例(食道2例,胃1例,结肠4例,直肠1例),位于腹腔9例(肠系膜2例,网膜2例,腹膜后5例)。临床表现无特异性,光镜下具有一定特征。随访7例,3例平滑肌瘤均显示预后良好,4例平滑肌肉瘤中3例复发,1例死亡。SMA阳性率100%(17/17),Desmin阳性率94%(16/17),CD117、CD34、S-100蛋白、PDGFRA及PKCtheta均为阴性表达。结论消化道及腹腔软组织平滑肌肿瘤少见,发生于消化道者多为良性,发生于腹腔者多为恶性。该肿瘤强表达SMA及Desmin,PDGFRA或PKC theta可作为与胃肠道间质瘤鉴别诊断的标记物。

Clinicopathological and immunohistochemical research on smooth muscle tumor of alimentary tract and abdominal soft tissue

Objective To investigate the cliniopathological and immunohistochemical features of smooth muscle tumor in alimentary tract and abdominal cavity.Methods Seventeen cases of smooth muscle tumor from alimentary tract and abdominal cavity were studied by clinicopathological analysis and immunohistochemical staining,and 7 of them accepted follow-up investigation.Results Among 17 smooth muscle tumor cases,7 from men and 10 from women,aged from 23 to 63 years old(49 on average).7 cases occurred in digest tract(2 from esophagus,1 from stomach,4 from colon,1 from rectum),while 9 cases occurred in abdominal cavity(2 from mesentery,2 from omentum,5 from retroperitoneum).No special clinical symptoms were found in these tumors,while some histopathological features were detected.3 follow-up cases of leiomyomas showed good prognosis,while 4 follow-up leiomyosarcomas cases showed 3 cases developed recurrence and 1 died.Immunohistochemically,the tumor showed positive for SMA(100%,17/17),Desmin(94%,16/17),while negative for CD117,CD34,S-100,PDGFRA and PKC theta.Conclusion The smooth muscle tumor rarely happens at alimentary tract and abdominal cavity.Those smooth muscle tumors occurring in alimentary tract are always leiomyoma,whereas the tumors occurring in abdominal cavity are generally leiomyosarcoma.The tumor has positive expression of SMA and Desmin,and besides,PDGFRA and PKC theta can be a helpful marker for differential diagnosis between the smooth muscle tumor and GIST.