Abstract：
Introduction BCOR::CCNB3-positive undifferentiated sarcomas are rare. Herein, we present clinicopathological features including immunohistochemical and molecular data, along with the radiological profile of 12 such tumors. Methods Tumors were tested for BCOR::CCNB3 fusion by reverse transcription polymerase chain reaction (RT-PCR) technique. Eight tumors were tested for EWSR1 and three for SS18 gene rearrangements by fluorescence in situ hybridization, and two for SS18::SSX fusion by fragment analysis. Results Ten of 12 patients were male with ages ranging between 4 and 17 years (median = 13, average = 14.4). Nine tumors occurred in bones and three in soft tissues (median size = 8 cm). Four of five tumors within the appendicular bones were metadiaphyseal and appeared as permeative lesions, invariably associated with cortical thickening. Three tumors displayed mineralization. Histopathologically, the tumors comprised round to epithelioid cells with round to oval to spindle-shaped nuclei, mostly diffusely arranged in a myxoid stroma with intervening thin-walled vessels. Immunohistochemically, tumor cells were positive for BCOR (10/11), SATB2 (8/9), TLE1 (5/6), cyclinD1 (4/4), and EMA (3/8). All tumors revealed BCOR::CCNB3 fusion transcript. Nine patients underwent neoadjuvant chemotherapy, including five who underwent surgical resection, with two patients, who received adjuvant radiation therapy. A single patient, each, underwent palliative chemotherapy and palliative radiotherapy, respectively. Four patients developed pulmonary metastasis and three developed local recurrences. Four patients were alive-with-disease and two were free-of-disease. Conclusions It is crucial to identify BCOR::CCNB3 fusion-positive sarcomas, given significant treatment-associated implications. Certain clinicoradiological, histopathological features, absent EWSR1 rearrangement and BCOR, SATB2, and TLE1 immunoexpression are useful for triaging these tumors for molecular testing. A review of the literature on these ultra-rare tumors, including their diagnostic mimics is presented.
摘要：
简介BCOR::CCNB3阳性未分化肉瘤是罕见的。在这里，我们提供临床病理特征，包括免疫组织化学和分子数据，以及12个这样的肿瘤的放射学特征。方法采用逆转录聚合酶链反应（RT-PCR）技术对肿瘤进行BCOR：：CCNB3融合检测。用荧光原位杂交法检测8个肿瘤的EWSR1和3个肿瘤的SS18基因重排,和两个用于SS18::SSX融合的片段分析。结果12例患者中有10例为男性，年龄在4至17岁之间（中位数=13，平均=14.4）。9个肿瘤发生在骨骼中，3个发生在软组织中（中位大小=8cm）。阑尾骨内的5个肿瘤中有4个是下骨干，表现为渗透性病变。总是与皮质增厚有关。三个肿瘤显示矿化。组织病理学,肿瘤由圆形到上皮样细胞组成，具有圆形到椭圆形到纺锤形的细胞核，大部分弥漫性排列在粘液样基质中，中间有薄壁血管。免疫组织化学，肿瘤细胞BCOR阳性（10/11），SATB2(8/9),TLE1(5/6),cyclinD1(4/4),和EMA（3/8）。所有肿瘤显示BCOR::CCNB3融合转录物。9例患者接受新辅助化疗,包括五名接受手术切除的人，有两个病人,接受辅助放射治疗的人。一个病人,每个,接受了姑息性化疗和姑息性放疗，分别。4例发生肺转移，3例发生局部复发。四名患者患有疾病，两名患者没有疾病。结论鉴定BCOR::CCNB3融合阳性肉瘤至关重要,考虑到与治疗相关的重大影响。某些临床放射学，组织病理学特征,没有EWSR1重排和BCOR，SATB2和TLE1免疫表达可用于分类这些肿瘤以进行分子测试。对这些超罕见肿瘤的文献进行回顾，包括他们的诊断模仿。
