Tumours with divergent müllerian differentiation of the uterine corpus

The uterus is formed by fusion of the paramesonephric (müllerian) ducts, which form not only the epithelium, but also the myometrium and serosa of the uterine corpus as well. For this reason, it is perhaps not surprising that a number of uterine neoplasms reflect the plasticity of the primitive müllerian cell and display divergent differentiation with both epithelial and mesenchymal morphology within the same tumour. This group of tumours includes carcinosarcoma (malignant mixed müllerian tumour), adenosarcoma, adenofibroma, adenomyoma, atypical polypoid adenomyoma, and endometrial stromal neoplasms with epithelial differentiation. Each tumour type will be reviewed, with an emphasis on advances and observations reported within the past decade.