Abstract：
A 7-year-old female spayed Bernese Mountain dog was presented for evaluation of hematuria. Incidentally, a right stifle sarcoma was diagnosed via cytology, which raised concern for histiocytic sarcoma (given the patient\'s signalment) versus another joint-associated sarcoma. Histopathology and immunohistochemistry revealed a CD18-negative, non-histiocytic origin cell population. Findings were consistent with a joint-associated grade II soft tissue sarcoma (STS). The patient\'s hematuria was progressive over 5 months, and urinary bladder transitional cell carcinoma (TCC) was diagnosed via cystoscopy and histopathology. An enlarged right medial iliac lymph node was identified on routine restaging via abdominal ultrasound 3 months later. Cytology of the lymph node revealed a markedly pleomorphic cell population, again raising concern for histiocytic sarcoma (HS). Other differentials included an anaplastic metastatic population from the joint-associated STS or the TCC. Immunocytochemistry revealed a cytokeratin-positive, CD18-, CD204-, and vimentin-negative cell population, consistent with a carcinoma. DNA was extracted from cytology slides to sequence cells for BRAF mutation status. Sequencing revealed a homozygous V596E (transcript ENSCAFT00845055173.1) BRAF mutation, consistent with the known biology of TCC. In neither case was HS truly present in this patient, but immunocytochemistry provided information that helped to optimize the patient\'s chemotherapy recommendations.
摘要：
介绍了一只7岁的雌性BerneseMountain犬，以评估血尿。顺便说一句,通过细胞学诊断出右侧窒息性肉瘤，这引起了对组织细胞肉瘤（考虑到患者的信号）与另一个关节相关肉瘤的关注。组织病理学和免疫组织化学显示CD18阴性，非组织细胞起源的细胞群。结果与关节相关的II级软组织肉瘤（STS）一致。患者血尿进行性超过5个月，膀胱移行细胞癌（TCC）通过膀胱镜检查和组织病理学诊断。3个月后，通过腹部超声进行常规重建，发现右侧内侧淋巴结肿大。淋巴结细胞学显示明显的多形性细胞群，再次引起对组织细胞肉瘤（HS）的关注。其他差异包括来自关节相关STS或TCC的间变性转移群体。免疫细胞化学显示细胞角蛋白阳性，CD18-,CD204-,和波形蛋白阴性细胞群，与癌症一致。从细胞学载玻片中提取DNA以对BRAF突变状态的细胞进行测序。测序显示纯合V596E（转录本ENSCAFT00845055173.1）BRAF突变，与已知的TCC生物学一致。在这两种情况下，这个病人都没有真正存在HS，但免疫细胞化学提供的信息有助于优化患者的化疗建议。
