Biopsy samples obtained with a 14-gauge needle provide the most accurate diagnosis, which correlates with the diagnosis made with the surgical excision biopsy technique.

The US features, although generally benign, are not specific. Tissue sampling with fine-needle aspiration biopsy is recommended. Core biopsy is necessary if a diagnosis cannot be made with the aspirate but is not performed initially because of the possibility of milk fistula formation.

Helical CT is insensitive and nonspecific compared with MR imaging for the preoperative staging of endometrial carcinoma. MR imaging remains the imaging modality of choice.

Staging with MR imaging has costs and accuracy similar to those of the current method of staging with intraoperative gross dissection of the uterus. In addition, MR imaging decreases the number of unnecessary lymph node dissections.