In October 2014, a case of mass skin lesions was reported in whitespotted char (Salvelinus leucomaenis) caught in the Nalycheva River on the Kamchatka peninsula (Russia). The proportion of affected fish was approximately 50% of the catch. Lesions of varying severity were noted from small tubercles to large single and confluent formations and ulcers. Papilloma‐like growths were found in the epidermal layer of the skin of the affected fish. Histopathological alterations included the following: submerged growth of epithelial cells, infiltration of inflammatory cells, oedema of scale pockets, resorption of scales, haemorrhages, local necrosis and an increased number of mucous cells. In the dermal layer of the skin, haemorrhages and extensive necrosis were recorded. Inflammation, necrosis and destruction of myocytes were found in the underlying musculature. This is the first documented case of papilloma‐like skin lesions found in salmonids in Kamchatka. The affected whitespotted char were deemed unsuitable as a food product due to their unsatisfactory appearance and impermissible levels of bacterial contamination of the muscles.

中文翻译：

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堪察加半岛（俄罗斯）白点黑点鲑（Salvelinus leucomaenis）中高度流行的乳头状瘤样皮肤病变病例

2014年10月，一例白斑病（Salvelinus leucomaenis）被困在堪察加半岛（俄罗斯）的纳利切瓦河上。受影响鱼类的比例约为渔获量的50％。从小结节到大的单个和汇合的形成和溃疡，发现了严重程度不同的病变。在受影响鱼的皮肤表皮层发现乳头状瘤样生长。组织病理学改变包括：上皮细胞浸没生长，炎性细胞浸润，鳞屑袋水肿，鳞屑吸收，出血，局部坏死和粘液细胞数量增加。在皮肤的真皮层中，记录有出血和广泛的坏死。在潜在的肌肉组织中发现了心肌细胞的炎症，坏死和破坏。这是在堪察加鲑鱼中发现的第一例乳头状瘤样皮肤病变病例。