Laboratory of Pathological Anatomy, Mohammed VI University Hospital, Faculty of Medicine and Pharmacy of Oujda, Mohammed First University, Oujda, Morocco.
Department of Trauma and Orthopaedics, Mohammed VI University Hospital, Faculty of Medicine and Pharmacy of Oujda, Mohammed First University, Oujda, Morocco.
Pan Afr Med J. 2023 Apr 25;44:199. doi: 10.11604/pamj.2023.44.199.39846. eCollection 2023.
Extraskeletal myxoid chondrosarcoma is a rare mesenchymal neoplasm of uncertain differentiation, characterized morphologically by abundant myxoid stroma, a multinodular growth pattern, and uniform cells arranged in strands, clusters, and reticular networks. It usually occurs in adults in the fifth decade, most often in the deep soft tissues of the proximal extremities. The molecular hallmark of this tumor, present in over 90% of cases, is the fusion of NR4A3 with EWSR1 at 22q12.2 or TAF15 at 17q12. Many other tumors with uniform tumor cells embedded in a myxoid matrix can mimic Extraskeletal myxoid chondrosarcoma, and the distinction can be difficult, often requiring immunohistochemistry and/or molecular testing. We herein report the case of an Extraskeletal myxoid chondrosarcoma that occurred in a 74-year-old woman who consulted for a slowly enlarging thigh mass, while highlighting the key morphologic, immunohistochemical, and molecular features of this rare type of soft tissue sarcoma, as well as a summary table gathering diagnostic features of relevance to the differential diagnosis.
骨外黏液样软骨肉瘤是一种罕见的间叶性肿瘤，分化不确定，其形态学特征为丰富的黏液样基质、多结节生长模式和均匀的细胞呈条索状、簇状和网状排列。它通常发生在 50 岁左右的成年人，最常发生在四肢近端的深部软组织。这种肿瘤的分子标志是超过 90%的病例中存在 NR4A3 与 EWSR1 在 22q12.2 或 TAF15 在 17q12 的融合。许多其他具有均匀肿瘤细胞嵌入黏液样基质的肿瘤可以模拟骨外黏液样软骨肉瘤，鉴别可能很困难，通常需要免疫组织化学和/或分子检测。本文报道了一例发生在 74 岁女性的骨外黏液样软骨肉瘤病例，该患者因大腿缓慢增大的肿块就诊，同时强调了这种罕见类型的软组织肉瘤的关键形态学、免疫组织化学和分子特征，并汇总了与鉴别诊断相关的诊断特征的表格。
