长骨釉质瘤及其去分化亚型临床病理分析

Clinicopathological analysis of adamantinoma of long bones and its dedifferentiated subtypes

目的探讨长骨釉质瘤尤其是去分化亚型的临床病理学特征。方法收集6例长骨釉质瘤,对其组织学形态、免疫组织化学进行分析,并复习相关文献。结果6例患者均为女性,发病年龄为10~45岁,平均21.8岁。5例发病于胫骨,1例在股骨颈。其中经典型3例,分化型2例,去分化型1例。组织学上经典型和分化型釉质瘤由异型性不明显的上皮成分及梭形间质细胞组成,经典型上皮成分明显,分化型上皮成分稀少。去分化型釉质瘤局灶可见经典型釉质瘤成分,去分化成分瘤细胞异型性明显、核染色深,核分裂数达8~15个/10个高倍镜。免疫组化显示经典型、分化型釉质瘤上皮成分不同程度表达AE1/AE3、EMA、CK5/6、P63等上皮标记物;去分化型釉质瘤Vimentin弥漫阳性和局灶EMA阳性,未见表达其它上皮标记物,Ki-67增殖指数达70%。去分化釉质瘤患者在瘤骨段切除11个月后复发,其余病例均未见复发及转移。结论相对于经典型和分化型釉质瘤,去分化型釉质瘤具有瘤细胞异型性明显、核分裂增多及免疫组化上皮标记物可表达缺失等特征,且具有更强的侵袭性及复发潜能。

Objective To investigate the clinicopathological features of adamantinoma of long bone(ALB)and especially its dedifferentiated subtypes.Methods The clinicopathological data of 6 cases of ALB were collected.Their histological morphology and immunohistochemistrical factors were analyzed and related literatures were reviewed.Results All the 6 patients were females,and the onset age was 10 to 45 years old(with an average age of 21.8 years),five with lesions on tibia and one on femoral neck.Among them,there were 3 cases of classic adamantinoma,2 differentiated adamantinoma and 1 dedifferentiated adamantinoma.Histologically,the classic and differentiated adamantinoma were composed of epithelial with inconspicuous atypia and spindle mesenchymal cells.The epithelial in the classic adamantinoma were prominent,while they were scanty in the differentiated subtype.Classic adamantinoma components can be seen in dedifferentiated adamantinoma,but the epitheliod tumor cells of the dedifferentiated adamantinoma exhibited obvious cell atypia,dark nuclei with frequent mitoses(up to 8~15/10 HPF).Immunohistochemically,the epithelial cells of the classic and differentiated adamantinoma expressed positive AE1/AE3,EMA,CK5/6,P63 and other epithelial markers.Components of dedifferentiated adamantinoma were diffusively positive for Vimentin and focally positive for EMA,but no other epithelial markers were expressed.The proliferation index of Ki-67 was up to 70%.All patients were followed up.Dedifferentiated adamantinoma recurred after 11 months since resection of the bone segment with tumor,while no recurrence or metastasis was found in the other cases.Conclusion Compared with classical and differentiated adamantinoma,dedifferentiated admantinoma are characterized by obvious atypia of tumor cells,increased mitoses and lack of expression of immunohistochemical epithelial markers,and have stronger invasiveness and recurrence potential.