Thickened endometrium caused by tamoxifen returns to normal following tamoxifen cessation

Endometrial thickening as seen on ultrasound scan of women on tamoxifen is well documented. To examine whether this phenomenon is reversible 20 women with thickened endometrium on scan but atrophic endometrium on further assessment underwent repeat ultrasound scan 6–11 months following tamoxifen cessation. Endometrial thickness reduced significantly in the majority of women off tamoxifen from a mean of 12.4 mm on tamoxifen to a mean of 7.8 mm off tamoxifen (P=0.0013).