Oshima Yuki, Nakagawa Yuri, Kashima Tsutae, Matsunaga Masako, Kushima Shohei, Tanaka Yukichi
Meat Inspection Station, Kanagawa Prefectural Government, 892-1 Sakai, Atsugi, Kanagawa 243-0022, Japan.
Kanagawa Prefectural Hospital Organization Kanagawa Children's Medical Center, 2-138-4 Mutsukawa, Minami-ku, Yokohama, Kanagawa 232-8555, Japan.
J Vet Med Sci. 2018 Jan 27;80(1):112-115. doi: 10.1292/jvms.17-0171. Epub 2017 Dec 1.
Renal mixed tumor characterized by the absence of nephrogenic blastema and the presence of predominant osteoid-producing osteoblast-like cells occurred in the kidney of a 6-month-old, hybrid, female pig. At the post-mortem examination, the tumor was found as a calcified grayish-white mass at the cranial end of the left kidney. Histologically the tumor consisted of 3 growth areas of poorly differentiated spindle cells, osteoid-producing osteoblast-like cells, and luminal epithelial cells. Transition from the spindle cells to the osteoblast-like cells or the luminal epithelial cells was observed. Immunohistochemically, the spindle cells and the osteoblast-like cells were consistently positive for β-catenin. Although the luminal epithelial cells and adjacent spindle cells were positive for cytokeratin, these 3 types of tumor cells were consistently negative for WT1. The tumor was diagnosed as primary renal mixed tumor characterized by marked proliferation of osteoblast-like cells with osteoid formation.
肾混合性肿瘤表现为无肾母细胞瘤成分，且存在以产生类骨质的成骨样细胞为主，该肿瘤发生于一头6个月大的杂种雌性猪的肾脏。尸检时，肿瘤表现为左肾头端一个钙化的灰白色肿块。组织学上，肿瘤由3个生长区域组成，分别为低分化梭形细胞、产生类骨质的成骨样细胞和管腔上皮细胞。观察到梭形细胞向成骨样细胞或管腔上皮细胞的转变。免疫组化显示，梭形细胞和成骨样细胞β-连环蛋白始终呈阳性。尽管管腔上皮细胞和相邻的梭形细胞细胞角蛋白呈阳性，但这3种肿瘤细胞WT1始终呈阴性。该肿瘤被诊断为以成骨样细胞显著增殖并形成类骨质为特征的原发性肾混合性肿瘤。
