Neoplasia is one of the main causes of euthanasia in geriatric captive nondomestic felids. However, few studies have examined oral tumors in these animals. We describe here the clinicopathologic features of gingival squamous cell carcinoma (SCC) in 2 lions ( Panthera leo) from separate zoologic collections. In both cases, the lions had a history of sialorrhea, bloody oral discharge, and anorexia. Autopsy findings in both lions were similar and were characterized by poorly circumscribed, friable, and bloody gingival masses with grossly apparent invasion of the mandibular bone; a pathologic fracture was observed in 1 case. Histologically, the masses consisted of poorly circumscribed, unencapsulated, densely cellular proliferations of neoplastic epithelial cells arranged in irregular islands, cords, and anastomosing trabeculae with formation of keratin pearls, which, coupled with positive immunohistochemistry for pancytokeratin, were diagnostic for SCC. Although no metastases were found in either animal, both lions were ultimately euthanized because of poor prognosis.

中文翻译：

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两只狮子在管理护理下患牙龈鳞状细胞癌

肿瘤是老年圈养非家养猫科动物安乐死的主要原因之一。然而，很少有研究检查这些动物的口腔肿瘤。我们在这里描述了来自不同动物收藏的 2 只狮子 (Panthera leo) 的牙龈鳞状细胞癌 (SCC) 的临床病理特征。在这两种情况下，狮子都有流涎、口腔带血和厌食的病史。两只狮子的尸检结果相似，其特点是牙龈肿块边界不清、易碎、血腥，下颌骨明显受到侵犯；病理性骨折1例。组织学上，肿块由边界不良、无包膜、密集的肿瘤性上皮细胞增生组成，排列成不规则的岛状、索状和吻合小梁，形成角蛋白珠，再加上全细胞角蛋白免疫组织化学阳性，诊断为鳞状细胞癌。尽管两只狮子都没有发现转移，但由于预后不良，两只狮子最终都被安乐死。