Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.
Department of Pathology and Laboratory Medicine, London Health Sciences Centre, Western University, London, ON, Canada.
Virchows Arch. 2020 Nov;477(5):725-732. doi: 10.1007/s00428-020-02870-0. Epub 2020 Jun 19.
The WHO Classification of Tumors of Soft Tissue and Bone divides rhabdomyosarcoma (RMS) into alveolar, embryonal, pleomorphic, and spindle cell/sclerosing types. Advances in molecular diagnostics have allowed for further refinement of RMS classification including the identification of new subtypes. Very rare RMS with epithelioid and spindle cell morphology, female predominance, marked osseous predilection, ALK expression, EWSR1/FUS-TFCP2 gene fusions, and highly aggressive clinical behavior have recently been recognized with only 23 cases reported in the English language literature. Herein, we report two additional cases with detailed clinicopathologic description and molecular confirmation. In brief, two young women presented each with a primary bone tumor-one with a frontal bone tumor and another with an osseous pelvic tumor. Both tumors showed epithelioid to spindle cell morphology, ALK expression, and EWSR1/FUS-TFCP2 gene fusions. Both patients died of disease less than 17 months from diagnosis despite administration of multiple lines of aggressive treatment. In addition, we review the literature and discuss differential diagnostic and potential treatment considerations.
世界卫生组织（WHO）软组织和骨肿瘤分类将横纹肌肉瘤（RMS）分为肺泡型、胚胎型、多形性和梭形细胞/硬化型。分子诊断学的进展使 RMS 分类进一步细化，包括确定新的亚型。最近发现了一种非常罕见的具有上皮样和梭形细胞形态、女性为主、明显骨倾向、ALK 表达、EWSR1/FUS-TFCP2 基因融合以及高度侵袭性行为的 RMS，仅在英文文献中报道了 23 例。在此，我们报告了另外两例具有详细临床病理描述和分子确认的病例。简而言之，两名年轻女性分别患有原发性骨肿瘤-一名患有额骨肿瘤，另一名患有骨盆骨肿瘤。这两个肿瘤均显示上皮样到梭形细胞形态、ALK 表达和 EWSR1/FUS-TFCP2 基因融合。尽管给予了多种强化治疗，但两名患者均在诊断后不到 17 个月因疾病死亡。此外，我们复习了文献并讨论了鉴别诊断和潜在的治疗注意事项。
