There are few published reports of canine rhabdomyosarcomas. In human paediatrics, rhabdomyosarcomas account for 5%‐10% of all tumours and >50% of soft tissue sarcomas. They have an aggressive biologic behaviour; most patients develop diffuse metastatic disease. Ezrin, a cytoskeleton linker protein, has been correlated with metastasis in a number of tumours, including rhabdomyosarcomas. The goal of this study was to describe dogs with non‐urinary rhabdomyosarcomas including clinical findings, ezrin expression and outcome. Twenty‐five dogs with rhabdomyosarcomas were identified from two institutions' databases. Signalment, primary tumour location, cytologic and histologic findings, metastatic sites, treatments, survival time and necropsy results were recorded. Immunohistochemical staining for ezrin expression was performed on archived samples; cellular localization of ezrin was characterized. The mean and median age of all patients was 4.3 and 2 years, respectively. Subcutaneous and retrobulbar/orbital were the most common primary tumour locations. Sixteen dogs had metastatic disease at diagnosis. Three dogs presented with diffuse disease where a primary tumour could not be identified. A round cell tumour was the initial diagnosis in 32% of cases, and 76% of cases required immunohistochemistry to establish the diagnosis. The median survival was 10 days. Twenty‐one cases had archived samples available for ezrin staining; all but one was positive and exhibited both membranous and cytoplasmic localization. Rhabdomyosarcomas occur in young dogs, may have a round cell appearance, and exhibit aggressive biologic behaviour. Given ezrin's defined role in metastasis, its observed expression in the tumours in this study suggest its possible role in canine rhabdomyosarcoma's aggressive biologic behaviour.

中文翻译：

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犬横纹肌肉瘤的生物学行为和ezrin表达：25例（1990-2012）。

关于犬横纹肌肉瘤的报道很少。在人类儿科中，横纹肌肉瘤占所有肿瘤的 5%~10%，占软组织肉瘤的 50% 以上。它们具有攻击性的生物行为；大多数患者发展为弥漫性转移性疾病。Ezrin 是一种细胞骨架连接蛋白，与许多肿瘤的转移有关，包括横纹肌肉瘤。本研究的目的是描述患有非泌尿横纹肌肉瘤的狗，包括临床发现、ezrin 表达和结果。从两个机构的数据库中确定了 25 只患有横纹肌肉瘤的狗。记录信号、原发肿瘤位置、细胞学和组织学发现、转移部位、治疗、存活时间和尸检结果。对存档样品进行了 ezrin 表达的免疫组织化学染色；表征了埃兹蛋白的细胞定位。所有患者的平均年龄和中位年龄分别为 4.3 岁和 2 岁。皮下和球后/眼眶是最常见的原发肿瘤位置。16 只狗在诊断时患有转移性疾病。三只狗出现弥漫性疾病，无法识别原发肿瘤。32% 的病例最初诊断为圆形细胞瘤，76% 的病例需要免疫组织化学来确定诊断。中位生存期为 10 天。21 个病例已存档样品可用于 ezrin 染色；除 1 个外，其余均呈阳性，并表现出膜和细胞质定位。横纹肌肉瘤发生在幼犬身上，可能有圆形细胞外观，并表现出攻击性的生物行为。鉴于埃兹蛋白在转移中的明确作用，本研究中观察到的其在肿瘤中的表达表明其可能在犬横纹肌肉瘤的侵袭性生物学行为中发挥作用。