Aggressive endometrial carcinoma in a breast cancer patient treated with tamoxifen with normal transvaginal ultrasonography. Case report.

Since tamoxifen therapy can induce endometrial disorders, surveillance schemes of women taking tamoxifen have been recommended. Transvaginal ultrasonography is a very sensitive test and therefore is often performed as a first-line screening test. We described a very atypical case of a high stage, high grade endometrial cancer associated with tamoxifen in a 64-year-old woman with a past history of breast cancer. This women was assessed yearly by ultrasonography and Pap smear. The cancer developed on a very thin endometrium and transvaginal ultrasonography failed to detect it. The patient remained asymptomatic up to the diagnosis. Normal endometrial cells in the Pap smear test were the only signs associated with this cancer. Surveillance strategies and significance of endometrial cells on the Pap smear are reviewed. In conclusion, TVUS can fail to detect cancers if the endometrial lining is not enlarged. In case of normal endometrial cells in the Pap smear, a careful evaluation should be performed.