伴炎症性恶性纤维组织细胞瘤样形态学特征的去分化脂肪肉瘤7例临床病理特征

Dedifferentiated liposarcomas with inflammatory malignant fibrous histiocytoma-likefeatures: a clinicopathological study of seven cases

目的探讨伴炎症性恶性纤维组织细胞瘤(inflammatory malignant fibrous histiocytoma,IMFH)样形态学特征的去分化脂肪肉瘤(dedifferentiated liposarcoma,DDLPS)的临床病理学及分子遗传学特征。方法回顾性分析7例伴IMFH样形态学特征的DDLPS的临床病理学及免疫表型特征,行HE及免疫组化染色,采用FISH法检测MDM2基因扩增情况,并复习相关文献。结果患者男性4例,女性3例,年龄41~78岁(中位年龄65岁);5例肿瘤位于腹膜后、1例位于腹股沟、1例位于阴囊/睾丸旁;低倍镜下肿瘤特征性地表现为异型肿瘤细胞散在分布于大量的炎症细胞背景之中,炎症细胞以中性粒细胞为主。FISH检测示7例肿瘤细胞均伴MDM2基因的簇状扩增。结论伴IMFH样形态学特征的DDLPS需与多种炎性病变、淋巴瘤或富含炎症细胞背景的软组织肿瘤相鉴别。免疫组化结合MDM2基因FISH检测有助于诊断与鉴别诊断。

Purpose To investigate the clinicpathological and molecular genetic characteristics of dedifferentiated liposar-comas(DDLPS)with inflammatory malignant fibrous histiocytoma(IMFH)-like features.Methods Seven cases of DDLPS with IMFH-like features diagnosed were enrolled in this study.These cases were analyzed by routine HE staining,immunohistochemistry and fluorescent in situ hybridization(FISH)on MDM2 gene.Related literatures were also reviewed.Results Among the seven patients,four were male and three were female.The age of onset was ranged from 41 to 78 years(mean,65 years).The sites of involvement were retroperitoneum(5 cases),groin(1 case)and scrotum/paratesticular area(1 case),respectively.Microscopically,the characteristic impression under low-power field was atypical tumour cells floating in a sea of inflammatory cells.The inflammatory cells mainly consisted of neutrophils.FISH detection showed that the tumor cells in all the 7 cases were accompanied by high-lever amplification of the MDM2 gene.Conclusion DDLPS with IMFH-like features needs to be distinguished from various inflammatory lesions,lymphoma,or soft tissue tumors rich in inflammatory cell background.Immunohistochemistry and FISH detection of MDM2 gene is helpful for its diagnosis and differential diagnosis.