乳腺原发性骨外粘液样软骨肉瘤(pEMC)很少见,迄今为止仅报道了少数病例。在这里,我们报告一例45岁女性乳腺原发性EMC病例.患者出现左乳房肿块1个月。乳房X光检查显示出一个相当有限的肿块,带有钙化的针状体。核心活检和切除标本显示粘液样软组织肿瘤,具有粘液样软骨肉瘤的组织学特征。坏死,出血,有丝分裂活性活跃。即使在广泛采样后,也没有发现恶性上皮成分。肿瘤细胞对波形蛋白表现出免疫反应性,S100,神经元特异性烯醇化酶,CD99和突触素,而上皮,肌上皮,乳腺谱系相关标记为阴性。由于高达81%的EMC案例包含t(9;22)(q22;q12),这导致22q12处的EWSRNA结合蛋白1基因(EWSR1)与核受体亚家族4(A组)融合,成员3基因在9q22。在我们的病例中检测到涉及EWSR1基因座的重排。全身PET-CT未发现任何其他肿块。提出了pEMC的诊断。患者接受了六个周期的5-氟尿嘧啶,环磷酰胺,和阿霉素.患者在最后一次随访时(手术后18个月)处于临床和放射学缓解。PET-CT及脑MRI均为阴性。总之,外科病理学家在处理乳腺粘液样软组织病变时,应将EMC纳入他们的鉴别中,特别是在芯针活检中。快速诊断乳房的EMC将使外科医生能够进行保守的乳房手术,而不是在其他原发性恶性乳腺肿瘤的情况下采取更彻底的方法。
Primary extraskeletal myxoid chondrosarcoma (pEMC) of the breast is rare and only a few cases have been reported to date. Herein, we report a
case of primary EMC of the breast in a 45-year-old female. The patient presented with a left breast mass for 1 month. Mammogram revealed a fairly circumscribed mass with spicules of calcifications. The core biopsy and resection specimen showed a myxoid soft tissue neoplasm with histologic features of a myxoid chondrosarcoma. Necrosis, hemorrhage, and brisk mitotic activity were present. No malignant epithelial element was identified even after extensive sampling. The tumor cells exhibited immunoreactivity for vimentin, S100, neuron specific enolase, CD99, and synaptophysin, while the epithelial, myoepithelial, and mammary lineage-associated markers were negative. As up to 81% of EMC cases harbor t(9;22)(q22;q12), this results in a fusion of EWS RNA-binding protein 1 gene (EWSR1) at 22q12 to the nuclear receptor subfamily 4, group A, member 3 gene at 9q22. A rearrangement involving the EWSR1 locus was detected in our
case. Whole body PET-CT did not reveal any other mass. A diagnosis of pEMC was rendered. The patient received six cycles of 5-Fluorouracil, Cyclophosphamide, and Adriamycin. The patient was in clinical and radiologic remission at the last follow-up (18 months post surgery). PET-CT and brain MRI were negative. In conclusion, surgical pathologists should include EMC in their differential while dealing with a myxoid soft tissue lesion of the breast, particularly in the core needle biopsies. An expeditious diagnosis of EMC of the breast would allow the surgeon to carry out conservative breast surgery instead of more radical approaches taken in cases of other primary malignant mammary neoplasms.