霍奇金样淋巴瘤（HLL）是一种罕见的猫肿瘤，具有与人类疾病相同的特征。 HLL 的标志是存在表达 CD30 和 CD20 的 Reed-Sternberg (RS) 细胞。本研究旨在阐明猫 HLL 的临床病理特征、免疫表型和克隆模式。 MyLav 实验室对 6 年期间淋巴结淋巴瘤的临床病理学和分子数据进行了全面的回顾性审查。已发现 24 例病例。所有猫均出现颌下或咽后淋巴结肿大。组织病理学检查显示具有低有丝分裂活性的中型至大型淋巴细胞的多灶性弥漫性增殖、散在的 RS 细胞以及包含 T 细胞、浆细胞和中性粒细胞的异质炎症浸润。此外，广泛的坏死是一致的发现。免疫组织化学显示肿瘤细胞中膜 CD20 和核 PAX5 表达存在差异，而 RS 细胞仅显示轻度至中度 CD20 阳性且 PAX5 阴性。在 21/24 例 (87.5%) 中，RS 细胞呈弥漫性 CD30 阳性。 PARR 分析表明，60% 的病例出现克隆性 B 细胞扩增，其余 40% 则表现出多克隆性。对于可进行随访的 10 只猫来说，预后总体良好，只有两只猫死于进行性疾病。总之，诊断猫 HLL 具有挑战性。 RS 细胞表达 CD30 和 CD20 应被视为该疾病的标志，但前提是排除间变性 B 细胞淋巴瘤和肉芽肿性淋巴结病等鉴别诊断。© 2024 John Wiley

Hodgkin-like lymphoma (HLL) is a rare neoplasm in cats that shares characteristics with the human disease. The hallmark of HLL is the presence of Reed-Sternberg (RS) cells expressing CD30 and CD20. This study aimed to elucidate the clinicopathologic features, immunophenotype and clonality patterns of feline HLL. A comprehensive retrospective review of clinicopathologic and molecular data of nodal lymphomas over a 6-year period was conducted in MyLav laboratory. Twenty-four cases were identified. All cats presented with submandibular or retropharyngeal lymphadenopathy. Histopathologic examination revealed a multifocal to diffuse proliferation of medium-to-large lymphoid cells with low mitotic activity, interspersed RS cells, and a heterogeneous inflammatory infiltrate comprising T-cells, plasma cells and neutrophils. In addition, extensive necrosis was a consistent finding. Immunohistochemistry showed a variable membranous CD20 and nuclear PAX5 expression in neoplastic cells, while RS cells displayed only mild to moderate CD20 positivity and were negative to PAX5. In 21/24 cases (87.5%), RS cells were diffusely CD30-positive. PARR analysis demonstrated clonal B-cell expansion in 60% of cases, with the remaining 40% exhibiting polyclonality. For the 10 cats with available follow-up, the prognosis was generally favourable, with only two cats succumbing to progressive disease. In conclusion, diagnosing feline HLL is challenging. The expression of CD30 and CD20 by RS cells should be considered a hallmark of the disease, but only after excluding differential diagnoses such as anaplastic B-cell lymphoma and granulomatous lymphadenopathy.© 2024 John Wiley & Sons Ltd.