Furukawa Satoshi, Hoshikawa Yumiko, Irie Kota, Kuroda Yusuke, Takeuchi Kazuya
Biological Research Laboratories, Nissan Chemical Corporation, 1470 Shiraoka, Shiraoka-shi, Saitama 349-0294, Japan.
J Toxicol Pathol. 2021 Apr;34(2):157-160. doi: 10.1293/tox.2020-0088. Epub 2021 Feb 28.
A swim bladder tumor was detected in one scoliotic medaka aged 22 weeks. The tumor was located in the dorsal abdominal cavity, with maximum dimension of 1,850 × 1,500 µm. No swim bladder lumen was identified, and the region where the swim bladder lumen would have been located, was replaced with adipose tissues. The tumor was a non-invasive, expansile, and encapsulated solid mass with a few cysts, and comprised a homogenous population of well-differentiated, densely packed, gas glandular epithelium-like cells. The tumor mass was connected to a rete mirabile that showed a hyperplastic capillary plexus; however, the tumor cells did not invade the rete mirabile, thereby revealing that the tumor was an adenoma originating from the gas glandular epithelium of the swim bladder. Since proliferative lesions in the swim bladder have been reported in some teleosts with skeletal deformations, including medaka, the occurrence of a spontaneous swim bladder tumor in teleosts is considered to be closely associated with various types of skeletal deformation, and spinal curvature in particular.
在一只22周龄的脊柱侧弯青鳉中检测到一个鳔肿瘤。肿瘤位于腹腔背部，最大尺寸为1850×1500微米。未发现鳔腔，鳔腔原本所在区域被脂肪组织取代。肿瘤是一个非侵袭性、膨胀性且有包膜的实性肿块，有一些囊肿，由均匀的高分化、密集排列的气腺上皮样细胞组成。肿瘤块与一个显示增生性毛细血管丛的奇静脉相连；然而，肿瘤细胞未侵犯奇静脉，从而表明该肿瘤是起源于鳔气腺上皮的腺瘤。由于在包括青鳉在内的一些有骨骼变形的硬骨鱼中已报道过鳔的增殖性病变，因此硬骨鱼中自发性鳔肿瘤的发生被认为与各种类型的骨骼变形密切相关，尤其是脊柱弯曲。
