Tochitani Tomoaki, Matsumoto Izumi, Hoshino Kohei, Toyosawa Kaoru, Kouchi Mami, Koujitani Takatoshi, Kimura Juki, Funabashi Hitoshi
Safety Research Laboratories, Dainippon Sumitomo Pharma Co., Ltd., 3-1-98 Kasugade-naka, Konohana-ku, Osaka 554-0022, Japan.
J Toxicol Pathol. 2013 Jun;26(2):187-91. doi: 10.1293/tox.26.187. Epub 2013 Jul 10.
The common marmoset (Callithrix jacchus) is now widely used in various research fields, including toxicology. However, information about the background pathology of this species is scarce. Here, we report a case of rhabdomyosarcoma that spontaneously occurred in a common marmoset. A 44-month-old male common marmoset was euthanized due to bilateral hind limb paralysis. At necropsy, a 2×2×5-cm intramuscular mass was observed in the lower right back. Histologically, the mass was mainly composed of interlacing bundles of spindle-shaped tumor cells. Immunohistochemically, the tumor cells were positive for myogenin, desmin, vimentin and alpha-smooth muscle actin. Ultrastructurally, the tumor cells contained bundles of myofilaments with Z-band-like structures. Thus, the tumor was diagnosed as a rhabdomyosarcoma. To our knowledge, this is the first report of spontaneous rhabdomyosarcoma that was definitely diagnosed in the common marmoset.
普通狨猴（Callithrix jacchus）如今在包括毒理学在内的各个研究领域中被广泛使用。然而，关于该物种背景病理学的信息却很匮乏。在此，我们报告一例在普通狨猴中自发发生的横纹肌肉瘤病例。一只44月龄的雄性普通狨猴因双侧后肢麻痹而被实施安乐死。尸检时，在右下腹背部观察到一个2×2×5厘米的肌内肿块。组织学上，该肿块主要由交错排列的梭形肿瘤细胞束组成。免疫组织化学检查显示，肿瘤细胞对肌生成素、结蛋白、波形蛋白和α-平滑肌肌动蛋白呈阳性反应。超微结构上，肿瘤细胞含有带有Z带样结构的肌丝束。因此，该肿瘤被诊断为横纹肌肉瘤。据我们所知，这是普通狨猴中首例被明确诊断的自发横纹肌肉瘤报告。
