Supplementary Material for: A Rare Case of High-Grade Spindle Cell Sarcoma of the Breast: A Case Report

Introduction: Spindle cell sarcomas are rare breast lesions which are difficult to diagnose due to resemblance with other breast lesions. Histopathological examination and immunohistochemical staining are essential for diagnosis. Case Presentation: We present a rare case of a 15-year-old female presenting with high-grade rapidly progressive spindle cell sarcoma of the breast, differentiated as phyllodes tumor, with axillary lymph node involvement. Her lesion, on the left breast, measured 16.9 × 10.1 × 13.7 cm. Histology revealed malignant neoplasm arranged in sheets and individual neoplastic cells with an epithelioid to spindled morphology with scant cytoplasm and irregular nuclear membranes. Immunohistochemistry showed weakly positive focal CD-99, and negative WT-1, Myogenin, Desmin, p63, Cytokeratin, Synaptophysin, and CD-34 markers. She was successfully managed with modified radical mastectomy and discharged with regular follow-up advised. Conclusion: Spindle cell sarcomas have a very aggressive course and prompt diagnosis, and management is mandatory for better patient outcomes. Modified radical mastectomy is the mainstay of treatment.

引言： spindle cell sarcomas（纺锤细胞肉瘤）作为一种罕见的乳腺病变，因其与其他乳腺病变的相似性而难以确诊。组织病理学检查和免疫组化染色对于诊断至关重要。病例报告：本文报道了一例15岁女性患者的罕见病例，她表现出高分级、快速进展的乳腺纺锤细胞肉瘤，被诊断为叶状肿瘤，并伴有腋下淋巴结受累。该患者的肿瘤位于左侧乳腺，大小为16.9 × 10.1 × 13.7厘米。组织学检查发现，恶性新生物呈片状排列，由单个肿瘤细胞组成，这些细胞具有上皮样至纺锤形的形态，胞浆稀少，细胞核膜不规则。免疫组化显示CD-99标记物呈弱阳性局灶性表达，而WT-1、Myogenin、Desmin、p63、Cytokeratin、Synaptophysin和CD-34标记物均呈阴性。患者接受了改良根治性乳腺切除术，并建议定期随访。结论：纺锤细胞肉瘤具有极为侵袭性的病程，及时诊断和管理对于改善患者预后至关重要。改良根治性乳腺切除术是治疗的主要手段。