子宫内膜未分化及去分化癌8例临床病理特点

Clinicopathologic characteristics of undifferentiated/dedifferentiated endometrial carcinoma

目的探讨子宫内膜未分化及去分化癌的临床特点、病理特征、诊断及鉴别诊断。方法筛选2005—2015年间解放军总医院病理科可明确诊断为子宫未分化癌、去分化癌的病例,观察并总结此类病例的临床特点、病理形态特征、免疫组化染色结果及特殊染色在诊断中的作用,并进行相关文献复习。结果符合该诊断的病例共8例,其中去分化癌6例,未分化癌2例;中位年龄55岁,6例为绝经后发生。临床表现以不规则阴道流血为主。FIGO分期IC期3例,IIB期2例,Ⅲ期2例,Ⅳ期1例。镜下均见小圆细胞肿瘤成分伴地图样坏死,浸润子宫肌壁深层,1例可见较大的肿瘤细胞及瘤巨细胞。部分瘤细胞似浆细胞样或横纹肌样,黏附性差,核分裂象平均>20个/10HPF。6例可见脉管癌栓;6例经多点取材,于肿瘤周边见高~中分化内膜样癌成分(<10%),故诊断为去分化癌。免疫组化染色结果显示小圆细胞成分的部分区域vimentin(+),上皮性标记物pan-CK、EMA、CK7和CK8/18至少有一种局灶(+),部分肿瘤细胞CD99、CD56及Syn(+),7例CD138(+);但ER、PR均(-)。4例见微卫星不稳定现象。网织染色显示肿瘤细胞呈小巢状分布。3例FIGOⅢ~Ⅳ期患者均死于肿瘤,平均生存期13.3个月,其余被随访患者恢复良好。结论子宫未分化及去分化癌罕见,鉴别诊断时需多种上皮性标记物联合使用,且至少有一种上皮性标记物局灶阳性方可诊断。网织染色能较好地与间叶来源的肉瘤进行鉴别。其分子机制尚待进一步研究。

Objective To study the clinical and pathological characteristics of undifferentiated/dedifferentiated endometrial carcinoma and to analyze the points of diagnosis and differential diagnosis. Methods The cases were collected in Department of Pathology of PLA General Hospital from January 2005 to December 2015. The clinical data, morphologic features, immunohistochemistry and special staining results, and the related literature were reviewed. Results 8 cases were conformed to the diagnosis, including 6 cases of dedifferentiated carcinoma and 2 cases of undifferentiated carcinoma. The median age was 55 years and there were 6 cases happened postmenopausally. Irregular vaginal bleeding was the most common symptom. FIGO stage was IC （ 3/8 ）, IIB（ 2/8 ）, Ⅲ （ 2/8 ） and Ⅳ （ 1/8 ）. Small round cells with necrosis and deep invading of the uterine could be seen in all of these cases, and giant tumor cell was only found in one case. Rhabdoid cells were noticed in some cases（4/8） and mitoses were numerous（ average 〉 20/HPF）. Vascular involvement could also be seen in most cases（6/8 ）. In 6 cases, we could see associated low-grade endometrioid carcinoma components （ 〈 10%）, and so the diagnosis of dedifferentiated carcinomas were established. Immunohistochemical staining showed that undifferentiated carcinomas were locally positive for Vimentin, CD99, CD56, Syn and at least positive for one kind of epithelial markers （e. g. , pan-CK, EMA, CK7, CK8/18 ）. Most of them were positive for CD138 and all of them were negative for ER, PR. 4 cases appeared as loss of mismatch repair protein expression and microsatellite instability. The Gomori collagen staining showed the tumor cells were nested. The patients of FIGO Ⅲ-Ⅳ were died in 10-18 months （average 13.3 months）, and the others were well recovered. Conclusions Undifferentiated/dedifferentiated endometrial carcinoma is a rare kind of tumor. A series of biomarkers should be used in the diagnosis and at least one kind of epithelial markers should be expressed. Gomori collagen staining can help us in differential diagnosis. Its molecular mechanism needs to be further studied.