Shiga Atsushi, Katoh Yoshitaka, Ito Tsuyoshi, Ohnuma-Koyama Aya, Takahashi Naofumi, Okazaki Yoshimasa, Harada Takanori
The Institute of Environmental Toxicology, 4321 Uchimoriya-machi, Joso-shi, Ibaraki 303-0043, Japan.
J Toxicol Pathol. 2019 Jul;32(3):181-187. doi: 10.1293/tox.2018-0046. Epub 2019 Apr 15.
An extraskeletal osteosarcoma was detected in the auricle of a 110-week-old female Wistar Hannover rat. Grossly, the tumor, measuring 15 mm in size, was observed in the subcutis as a solid and hard mass. Histologically, the majority of the mass comprised mature, compact bone. It was surrounded by neoplastic cells showing a variety of histologies, such as sarcoma, not otherwise specified, and myxosarcoma away from the bone-forming region. However, these different histological regions were considered to be components of a single bone tumor, based on the common expression of osterix and a similar mixture of constituent cells in each region. The tumor was diagnosed as an extraskeletal osteosarcoma because of the presence of infiltrative growth and abnormal mitosis and its development in the auricle without attachment to the skeleton. The present case is a rare histological type of an extraskeletal osteosarcoma with independent and different histological elements in rats.
在一只110周龄的雌性Wistar Hannover大鼠的耳廓中检测到一例骨外骨肉瘤。大体观察，肿瘤大小为15 mm，位于皮下，为实性硬块。组织学上，大部分肿块由成熟的致密骨组成。在远离骨形成区域的部位，其周围有显示多种组织学类型的肿瘤细胞，如未另行特指的肉瘤和黏液肉瘤。然而，基于osterix的共同表达以及每个区域中组成细胞的相似混合情况，这些不同的组织学区域被认为是单个骨肿瘤的组成部分。由于肿瘤存在浸润性生长和异常有丝分裂，且在耳廓中发生而未与骨骼相连，该肿瘤被诊断为骨外骨肉瘤。本病例是大鼠中一种罕见的组织学类型的骨外骨肉瘤，具有独立且不同的组织学成分。
