To determine if Fluorescein systemic injection during hysterectomy procedure can be useful in revealing the depth of endometrial cancer invasion.

All research participants will receive fluorescein injection through their existing intravenous line during their operative procedure for endometrial cancer staging. This will consist of one ampule (5 cc) injected intravenously prior to ligation of the uterine arteries. After the uterus is removed it will be sent to surgical pathology for evaluation as per routine care. The pathologist will open the uterus and evaluate the endometrium. He or she will then cut into the myometrium in an area most suspicious for invasion. The cross section of the myometrium and endometrium will be photographed while exposed to a Woods lamp. The normal myometrium will have a yellow fluorescent appearance under the Woods lamp. The cancerous tissue will have minimal fluorescence. The measurement will be taken estimating the depth of invasion of the cancer into the myometrium on the basis of its physical appearance under the Woods lamp. Cross-sectioning of the uterus is routine procedure by pathology for the intra-operative evaluation of endometrial cancer. This information routinely is provided in order to determine if lymph node staging is necessary.

The area that was measured and photographed will then be prepared for a frozen section to document depth of invasion. This is the standard procedure performed during an endometrial staging. The depth of invasion on the frozen section will be recorded. This same area will undergo histologic confirmation by permanent pathology to determine depth of invasion. The frozen section is part of routine standard of care in evaluation of endometrial cancer.

Inclusion Criteria:

• Documented endometrial cancer and scheduled for hysterectomy as part of their treatment.
• No known allergy to fluorescein dye
• Ability to understand and sign informed consent
• 18 years of age or older

Exclusion Criteria:

• Prior hysterectomy
• Known sensitivity to fluorescein dye

On day of assessment.

The protocol was updated and the other outcome measures are no longer part of the study, so they were removed. Deleted outcome measures were not pre-specified primary or secondary outcome measures.