腹腔上皮样炎性肌纤维母细胞肉瘤临床病理特征

Clinicopathologic characteristics of intra-abdominal epithelioid inflammatory myofibroblastic sarcoma

上皮样炎性肌纤维母细胞肉瘤(epithelioid inflammatory myofibroblastic sarcoma,EIMS)是炎性肌纤维母细胞肿瘤(inflammatory myofibroblastic tumor)的罕见特殊亚型,其临床病理特征、免疫表型及分子遗传学均有特殊性.本文报道1例腹腔EIMS,患者男性,46岁,因反复腹痛腹胀10余天入院.肉眼:肿物结节状不规则,大小17 cm×12 cm×8 cm,切面灰白灰黄色,实性,鱼肉样,质中,包膜似完整.镜下:以中性粒细胞为主的炎症性黏液样背景中圆形至上皮样细胞散在分布,肿瘤细胞泡状核,核仁明显,胞质嗜双色性或嗜酸性.免疫组织化学:肿瘤细胞ALK特征性核膜阳性,CD30、Vimentin胞质弥漫强阳性;Fish检测ALK基因信号分离.EIMS生物学行为侵袭性强,肿瘤易快速复发转移,预后很差,临床主要治疗方法为手术切除辅以放、化疗.

Epithelioid inflammatory myofibroblastic sarcoma（EIMS） is a rare subtype of inflammatory myofibroblastic tumor（IMT）,and its clinicopathologic characteristics,immune phenotypes and molecular genetics are particular.Here we report a case of intraabdominal EIMS.A male patient,aged 46 years,was admitted due to recurrent pain and distension in the abdomen for more than 10 days.Grossly,a nodular mass measuring 17 cm × 12 cm × 8 cm was observed,and it was grayish yellow and solid,had a fish-like cut surface,and tended to be well circumscribed with medium consistency.Microscopically,round to epithelioid cells were scattered in a mucinous and neutrophil-predominant inflammatory background,and the tumor cells had vacuolated nuclei,prominent nucleoli,and amphophilic or eosinophilic cytoplasm.Immunohistochemically,the tumor cells showed typical nuclear membrane staining for ALK,diffuse and strong cytoplasmic staining for CD30 and Vimentin.Split signals were detected by FISH using break-apart probes to ALK.The aggressive biological behavior of EIMS increases the risk of recurrence and metastasis,and thus the prognosis is poor.Surgical resection is the main treatment for EIMS,with radiation therapy or chemotherapy as a postoperative adjunct.