Oon Ming Liang, Wu Bingcheng, Lee Jaslyn Jie Lin, Tan Charmaine, Seet Ju Ee, Michal Michael, Petersson Fredrik
Department of Pathology, National University Hospital, Singapore, Singapore.
Department of Otolaryngology - Head & Neck Surgery, National University Hospital, Singapore, Singapore.
Virchows Arch. 2025 May 8. doi: 10.1007/s00428-025-04119-0.
SS18::POU5F1-fused sarcomas are rare tumors that show an undifferentiated round cell morphology. We report for the first time a case of SS18::POU5F1-fused sarcoma occurring in the parotid gland, with a highly unusual biphasic morphology comprising of epithelioid/undifferentiated round cell component and a ganglioneuromatous component consistent with divergent differentiation. We illustrate the cytology, histomorphological, immunohistochemical profile of the tumor, and show that both components of the tumor share a common origin. We discuss the differential diagnoses of this tumor, discuss its possible histogenesis, and perform a broad review of the literature covering this uncommon tumor.
SS18::POU5F1融合性肉瘤是一种罕见肿瘤，具有未分化的圆形细胞形态。我们首次报告了1例发生于腮腺的SS18::POU5F1融合性肉瘤，其具有高度不寻常的双相形态，由上皮样/未分化圆形细胞成分和与分化异常一致的神经节神经瘤成分组成。我们阐述了该肿瘤的细胞学、组织形态学和免疫组化特征，并表明肿瘤的两个成分具有共同起源。我们讨论了该肿瘤的鉴别诊断，探讨了其可能的组织发生，并对涵盖这种罕见肿瘤的文献进行了广泛综述。
