This phase III trial compares the effect of sentinel lymph node mapping to standard lymph node dissection in reducing the risk of swelling in the legs (lymphedema) in patients undergoing a hysterectomy for stage I endometrial cancer. Standard lymph node dissection removes lymph nodes around the uterus during a hysterectomy to look for spread of cancer from the uterus to nearby lymph nodes. Sentinel lymph node mapping uses a special dye and camera to look for cancer that may have spread to nearby lymph nodes. Comparing the results of the procedures may help doctors predict the risk of long-term swelling in the legs.