Spontaneous malignant mixed Mullerian tumor in a Wistar rat: a case report including immunohistochemistry.

摘要

This report presents a rare, spontaneous, heterologous, malignant mixed Mullerian tumor observed in a 98-week-old untreated Wistar rat. At necropsy, the right uterine horn was dilated and contained a mass of approximately 10x15 mm. Histopathologically the mass consisted of 2 parts with different morphologic characteristics, a polypoid mass protruding into the uterine lumen and a more solid part that replaced the adjacent uterine wall. The solid part exhibited characteristics of a highly infiltrative adenocarcinoma, whereas the composition of the polypoid mass was heterogeneous, consisting of a variety of benign and malignant epithelial and mesenchymal elements. The epithelial components included well-differentiated endometrial and squamous epithelium juxtaposed to carcinosarcomatous areas. The mesenchymal components consisted of well-differentiated cartilage and bone along with chondrosarcomatous, rhabdomyomatous, and other mesenchymal elements. Immunohistochemical analysis further supported the diagnosis of malignant mixed Mullerian tumor.Digital Object Identifier http://dx.doi.org/10.1177/0300985810374840