When evaluating the endometrium, the first-line imaging modality is the ultrasound (US). The thickness of normal endometrium in women receiving tamoxifen remains controversial. However, it has been observed that women undergoing tamoxifen treatment usually have a thicker endometrium, ranging from 9 to 13 mm, besides the finding of cystic spaces.

The patient presented above has been under vigilance since the beginning of tamoxifen treatment, doing transvaginal US periodically to study the endometrial abnormalities that were detected as soon as the patient initiated the tamoxifen intake. No changes were observed throughout the period of the drug therapy.

Contributed by Dr. Guilherme Pioli Resende M.D. and Dr. Gabriela Aquino Schneider M.D.