Villous papyraceous: an unusual cause of tamoxifen-induced postmenopausal bleeding

We describe an unusual histological finding in a woman with postmenopausal bleeding who was being treated with tamoxifen for breast cancer.

This patient presented with a history of postmenopausal bleeding, 4 years after her last period. Pelvic ultrasound showed a thickened cystic endometrium and bulky uterus. A diagnostic endometrial aspiration biopsy by Pipelle was performed; at this time, urinary beta-human chorionic gonadotropin was negative.

Histology showed villous papyraceous (sclerosed and mummified chorionic villi) in a background of scanty atrophic endometrium.

Tamoxifen has dual estrogenic and antiestrogenic effects; the estrogenic effects have been associated with ovulation induction in premenopausal women. This effect, however, has not been documented in postmenopausal women. We conclude that the presence of chorionic villi is, in this instance, likely to be a tamoxifen-mediated effect.