Abstract：
Diagnosis of soft tissue tumors is often challenging, given the large number of entities, often with non-specific or overlapping morphology. Although morphology still plays an important part in diagnostic process, additional studies including immunohistochemistry and molecular genetics are often needed to arrive at correct diagnosis. We report a case of 61-year-old male with subcutaneous tumor in right hip area, that was surgically removed. The tumor was composed of uniform bland spindle cells in mild to moderately cellular myxoid nodules, with limited areas of collagenization and the diagnosis of low grade fibromyxoid sarcoma was made. The tumor recurred 3 years after the initial diagnosis and the new sample showed a high-grade round cell sarcoma with limited residual low-grade areas and non-specific immunoprofile after extended immunohistochemical work-up. Molecular analysis demonstrated ZC3H7B::BCOR fusion. Sarcomas with ZC3H7B::BCOR fusion occurring outside of uterus are exceedingly rare. A comprehensive review of previously published cases and a short discussion about classification of the entity is provided, together with data about morphology and immunoprofile of the lesions. The case also underscores the necessity of extended work up of soft tissue tumors with unusual immunohistochemical or morphological features in order to accurately assess their biological potential.
摘要：
软组织肿瘤的诊断通常具有挑战性。鉴于实体数量众多，通常具有非特异性或重叠形态。尽管形态学在诊断过程中仍然起着重要的作用,通常需要进行包括免疫组织化学和分子遗传学在内的其他研究才能得出正确的诊断.我们报告一例61岁男性右髋部皮下肿瘤，手术切除的.肿瘤由轻度至中度细胞粘液样结节中的均匀平淡的梭形细胞组成，在有限的胶原化区域和低级别纤维粘液样肉瘤的诊断。最初诊断后3年，肿瘤复发，新样本显示为高级别圆形细胞肉瘤，经过长时间的免疫组织化学检查后，残留的低级别区域有限，并且具有非特异性免疫特征。分子分析表明ZC3H7B::BCOR融合。子宫外发生ZC3H7B::BCOR融合的肉瘤极为罕见。提供了对以前发表的案例的全面审查，并对实体的分类进行了简短的讨论，以及有关病变形态和免疫特征的数据。该病例还强调了对具有异常免疫组织化学或形态学特征的软组织肿瘤进行扩展工作的必要性，以准确评估其生物学潜力。
