This is an incomplete hydatidiform mole. They contain incomplete fetal parts including stem cells which are trisomy and give rise to unstructured tissue.

I know that complete moles do not contain fetal tissue (i.e. only chorionic villus, cytotrophoblast, and syncyciotrophoblasts) and partial mole as fetal tissue, chorionic villus, cytotrophoblast, and syncyciotrophoblast. Obviously hematopoietic stem cells are fetal parts as they turn into blood cells, but what is the overall definition of fetal parts?