Ibi Kanata, Chiba Shiori, Koyama Naomi, Hashimoto Kazuto, Nejishima Hiroaki
Kaken Pharmaceutical Co., Ltd., Shizuoka Research Center, 301 Gensuke, Fujieda, Shizuoka 426-8646, Japan.
J Toxicol Pathol. 2021 Apr;34(2):147-150. doi: 10.1293/tox.2020-0083. Epub 2021 Jan 18.
Extraskeletal osteosarcoma is extremely rare in humans and animals, especially in rodents. This is the first case report on spontaneous extraskeletal osteosarcoma in the neck skeletal muscle of a Crlj:CD1 (ICR) mouse (36 weeks, dead). Necropsy revealed a solid white mass located in the neck skeletal muscle (scalenus muscle). Histological examination showed that the tumor consisted of atypical polygonal cells, a small osteoid clump, and bone tissue. Mitotic figures were observed. Serial sections showed that neoplastic cells lacked clear invasive proliferation to adjacent normal skeletal muscle and continuity with normal bone tissue. Immunohistochemical analysis showed that the neoplastic cells were positive for osteocalcin, osterix, vimentin, and S-100. Based on these results, the tumor was diagnosed as extraskeletal osteosarcoma in the neck skeletal muscle.
骨外骨肉瘤在人类和动物中极为罕见，尤其是在啮齿动物中。这是首例关于Crlj:CD1（ICR）小鼠（36周龄，已死亡）颈部骨骼肌自发性骨外骨肉瘤的病例报告。尸检发现颈部骨骼肌（斜角肌）有一个实性白色肿块。组织学检查显示，肿瘤由非典型多边形细胞、少量类骨小团块和骨组织组成。观察到有丝分裂象。连续切片显示肿瘤细胞对相邻正常骨骼肌缺乏明显的浸润性增殖，且与正常骨组织无连续性。免疫组织化学分析显示肿瘤细胞骨钙素、osterix、波形蛋白和S-100呈阳性。基于这些结果，该肿瘤被诊断为颈部骨骼肌骨外骨肉瘤。
