摘要目的 探讨伴有BCOR基因易位的高级别子宫内膜间质肉瘤(HGESS)临床病理学特征、分子遗传学改变及其鉴别诊断.方法 收集2016至2018年复旦大学附属肿瘤医院病理科会诊的5例BCOR基因易位HGESS,对患者临床资料、组织学、免疫组织化学及分子病理学改变进行观察分析.结果 患者年龄45~55岁(中位年龄48岁),临床常表现为不规则阴道出血及腹痛.肿瘤位于肌壁间或凸向宫腔.镜下观察:肿瘤细胞疏密不均,呈舌状浸润或穿插性生长;梭形肿瘤细胞有轻‐中度异型性,无明显多形性,核分裂象易见,间质可见显著的黏液样变性或胶原形成;肿瘤富于小血管,内皮细胞增生、肿胀,未见明显的螺旋动脉或厚壁大血管;坏死及出血常见.5例均表达CD10,不表达h‐caldesmon;1例部分性表达结蛋白及平滑肌肌动蛋白(SMA),其余4例均不表达;1例同时表达雌激素受体(ER)、孕激素受体(PR),其余4例仅表达其中一项;BCOR表达3+者3例,2+者1例,阴性1例;5例均有cyclin D1表达,阳性细胞≥70%者为2例;Ki‐67阳性指数10%~30%.经荧光原位杂交(FISH)检测,所有肿瘤均存在BCOR基因易位.5例中2例曾被诊断为黏液性平滑肌肉瘤,2例为梭形细胞肉瘤,1例为低级别内膜间质肉瘤(LGESS).3/5患者在1年内复发、转移或死亡.结论 伴有BCOR基因易位的HGESS具有特殊的形态及免疫组织化学特征,预后较差,易被误诊为黏液性平滑肌肉瘤、LGESS或未分化子宫肉瘤等,明确诊断该病有重要的临床病理学意义.对于诊断和鉴别困难的病例,分子病理学检测是有力的证实和补充.

abstractsObjective To investigate clinicopathological, cytogenetic features and differential diagnoses of high grade endometrial stromal sarcoma(HGESS) with BCOR gene rearrangement. Methods Five cases of HGESS with BCOR rearrangement were collected from consultant files (2016-2018) at Fudan University Shanghai Cancer Center. Interphase FISH was performed using a dual color break‐apart probe. The clinical data, histologic features and immunohistochemical findings were reviewed. Results All 5 cases occurred in adult women with a median age of 48 (range, 45-55) years. Abdominal pain and abnormal vaginal bleeding were the most common symptoms. Microscopically, the tumors showed mainly tongue‐like and/or intersecting myometrial invasion. Stromal myxoid matrix and/or collagen plaques were prominent in all the cases. Most tumors consisted of uniform, haphazard fascicles of short spindle cells with mild to moderate nuclear atypia. Mitotic figures and necrosis were easily identified. Significant nuclear pleomorphism was not seen. Most tumors were rich in thick‐walled small vessels. Prominent perivascular tumor cell whorling seen in conventional low‐grade endometrial stromal sarcoma was not seen. All tumors expressed CD10 with only focal or absent desmin, SMA and/or h‐caldesmon staining. ER or PR expression was seen in 4 tumors and 1 tumor showed both marker expression. Diffuse cyclin D1 was present in 2 tumors. BCOR immunoreactivity was present with strong staining in 3 cases and moderate staining in 1 case respectively. Ki‐67 index ranged from 10% to 30%. Fluorescence in situ hybridization confirmed chromosomal aberration of BCOR gene in all tumors, that were previously diagnosed as myxoid leiomyosarcoma (2 cases), spindle cell uterine sarcoma (2 cases) and low‐grade endometrial stromal sarcoma (1 case). Limited follow‐up information revealed that 3/5 patients developed tumor recurrence, metastasis or death within one year. Conclusion BCOR rearranged HGESS has distinct morphological features and aggressive clinical behavior. In the presence of significant overlapping morphologic features between BCOR rearranged HGESS and other myxoid uterine mesenchymal tumors, especially myxoid leiomyosarcoma, molecular analysis is essential for accurate diagnoses.