The glands are well-differentiated and show angulation or branching. Cytologic atypia is minimal. The grading system currently used for endometrioid adenocarcinomas is the one proposed by International Federation of Gynecology and Obstetrics (FIGO). If the tumor contains no more than 5% of solid, non-morular component, it is Grade 1. Grade 1 tumors make up approximately 50% of endometrial adenocarcinomas.