Most surgeons will remove lymph nodes for cancers that are high grade (grades 2 and 3), for cancers of all grades that are deeply invasive into the muscle, and for all papillary serous and clear cell cancers. That is because these cancers are at high risk for lymph node involvement. If you have evidence of ovarian involvement or enlarged lymph nodes, the lymph nodes should be removed.
Beyond this, there are multiple ways a surgeon can determine if lymph nodes are involved in uterine cancer. The first is at the time of surgery—when the lymph nodes are removed at the time of the hysterectomy. The second method is by doing a biopsy with a needle. The health care provider performing the needle biopsy is usually aided by radiology. Using a CT scan machine, the needle can be guided to the suspicious area. The third technique is by PET/CT scan. In this combined scan, abnormal active areas are correlated with areas that are also enlarged, and if both are present in the lymph nodes in a woman with cancer, it is considered proof of metastatic disease. In such a case, your doctor may not even proceed to a biopsy or excision.
For grade 1 cancers, the surgeon may wait until the uterus has been removed to make a final decision about the lymph nodes. A “frozen section” of the uterus is obtained while you are asleep to assess how invasive into the muscle of the uterus your cancer is. If your cancer is more than halfway through the muscle of the uterus (the myometrium) then removal of the lymph nodes should be strongly considered.