Abstract：
BACKGROUND: Biphenotypic sinonasal sarcoma (BFSS) is a topographically specific low-grade sarcoma that was first described only 10 years ago. The term biphenotypic comes from the co-expression of markers of muscle differentiation and neural crest that is characteristic for this tumor.
METHODS: A 78-year-old woman manifested with prolonged breathing difficulties through the left nasal passage. Rhinoendoscopy and CT scans showed an obturation of the middle and posterior part of the left nasal cavity by a polypoid tumor mass with a stalk in the ethmoid sinus. It spread into the nasopharynx. The tumor was resected and extracted from the nasopharynx through the oral cavity. Grossly, it was a compact polyp measuring 6 × 3,5 × 3cm. Histology revealed a uniform neoplastic spindle cell population arranged in a fascicular pattern. It expres-sed S100 protein, smooth muscle actin, calponin and muscle-specific actin. Molecular genetic analysis of the tissue showed PAX3:: MAML3 gene fusion. The findings confirmed a dia-gnosis of BFSS.
CONCLUSIONS: BFSS is a very rare, locally aggressive malignant tumor without metastatic potential. In contrast to other malignancies in a given locality, it possesses a relatively favorable prognosis. In bio-psy practice, the pathologists knowledge of this unique histopathological entity is principal because it should be always considered when encountering a low-grade spindle cell neoplasia arising in the sinonasal region.
METHODS: A 78-year-old woman manifested with prolonged breathing difficulties through the left nasal passage. Rhinoendoscopy and CT scans showed an obturation of the middle and posterior part of the left nasal cavity by a polypoid tumor mass with a stalk in the ethmoid sinus. It spread into the nasopharynx. The tumor was resected and extracted from the nasopharynx through the oral cavity. Grossly, it was a compact polyp measuring 6 × 3,5 × 3cm. Histology revealed a uniform neoplastic spindle cell population arranged in a fascicular pattern. It expres-sed S100 protein, smooth muscle actin, calponin and muscle-specific actin. Molecular genetic analysis of the tissue showed PAX3:: MAML3 gene fusion. The findings confirmed a dia-gnosis of BFSS.
CONCLUSIONS: BFSS is a very rare, locally aggressive malignant tumor without metastatic potential. In contrast to other malignancies in a given locality, it possesses a relatively favorable prognosis. In bio-psy practice, the pathologists knowledge of this unique histopathological entity is principal because it should be always considered when encountering a low-grade spindle cell neoplasia arising in the sinonasal region.
摘要：
背景：双表型鼻窦肉瘤（BFSS）是一种地形特异性低度恶性肉瘤，仅在10年前首次被描述。术语双表型来自肌肉分化和神经c标记的共表达，这是这种肿瘤的特征。
方法：一名78岁的女性通过左鼻道表现为长期呼吸困难。鼻内窥镜检查和CT扫描显示左鼻腔的中后部被筛窦中的息肉样肿瘤肿块阻塞。它扩散到鼻咽部。切除肿瘤并通过口腔从鼻咽中取出。严重的,这是一个紧凑的息肉，大小为6×3,5×3cm。组织学显示，成束状排列的肿瘤梭形细胞群均匀。它表达了S100蛋白，平滑肌肌动蛋白，钙蛋白和肌肉特异性肌动蛋白。组织的分子遗传学分析显示PAX3::MAML3基因融合。这些发现证实了BFSS的诊断。
结论：BFSS是非常罕见的，没有转移潜力的局部侵袭性恶性肿瘤。与特定地区的其他恶性肿瘤相比，预后相对较好。在生物心理学实践中，病理学家对这种独特的组织病理学实体的了解是主要的，因为当遇到在鼻窦区域出现的低级梭形细胞瘤时，应始终考虑它。
方法：一名78岁的女性通过左鼻道表现为长期呼吸困难。鼻内窥镜检查和CT扫描显示左鼻腔的中后部被筛窦中的息肉样肿瘤肿块阻塞。它扩散到鼻咽部。切除肿瘤并通过口腔从鼻咽中取出。严重的,这是一个紧凑的息肉，大小为6×3,5×3cm。组织学显示，成束状排列的肿瘤梭形细胞群均匀。它表达了S100蛋白，平滑肌肌动蛋白，钙蛋白和肌肉特异性肌动蛋白。组织的分子遗传学分析显示PAX3::MAML3基因融合。这些发现证实了BFSS的诊断。
结论：BFSS是非常罕见的，没有转移潜力的局部侵袭性恶性肿瘤。与特定地区的其他恶性肿瘤相比，预后相对较好。在生物心理学实践中，病理学家对这种独特的组织病理学实体的了解是主要的，因为当遇到在鼻窦区域出现的低级梭形细胞瘤时，应始终考虑它。
