Uterine Carcinosarcoma in a 2-year-old Female Wistar Hannover GALAS Rat

Abstract

Carcinosarcomas are rare tumors in humans as well as rats and most commonly occur in the uterus. Recently, we observed a case of incidental carcinosarcoma of the uterus in a female Wistar Hannover GALAS [BrlHan:WIST@ Jcl (GALAS)] rat at 2 years of age. Histopathologically, the tumor was characterized by an admixture of malignant epithelial and nonepithelial elements. The carcinomatous components represented a type of endometrial carcinoma, consisting of glandular and solid proliferation of large-sized tumor cells. Prominent mitoses and tumor cell invasion were observed. The sarcomatous components were characterized by multifocal proliferation of severe atypical cells with cartilage matrix and were diagnosed as chondrosarcoma. Transitions between carcinomatous and sarcomatous components were observed, and many tumor cells in the solid lesion showed immunohistochemical reactivity with both cytokeratin and vimentin. Based on these findings, this tumor was diagnosed as a uterine carcinosarcoma. This is the first report of uterine carcinosarcoma in Wistar Hannover GALAS [BrlHan:WIST@Jcl (GALAS)] rats.

Proceedings of the 2013 National Toxicology Program Satellite Symposium

“…Heterologous types contain mesenchymal tissues not normally present in the uterus, such as skeletal muscle, cartilage, or bone (Figure 11D). MMMT is a very rare, spontaneous neoplasm in animals and has been previously diagnosed in one cat (Nicotina, Zanghi, and Catone 2002), one rabbit (Goto et al 2006), five Lewis rats (Kaspareit-Rittinghausen and Deerberg 1990), and three Wistar rats (Takami et al 2011; Van den Brink-Knol and van Esch 2010), though it has never been reported as a treatment-related finding in animals.…”