USMLE Step 1 Pathology Practice Test

In utero exposure to diethylstilbestrol (DES), a synthetic estrogen, is notably associated with clear cell adenocarcinoma of the vagina. This condition occurs primarily in daughters of women who took DES during pregnancy, particularly between the 1940s and 1970s. The risk of developing this rare form of cancer in females exposed to DES in utero is significantly heightened, with clear cell adenocarcinoma being a malignant neoplasm characterized by its unique histological features.

The mechanism behind this association involves hormonal alterations due to DES exposure, leading to changes in the development of the female reproductive tract. The exposure can result in structural abnormalities in the vagina, cervix, and uterus, predisposing individuals to various gynecological issues, including cancer.

While osteosarcoma, chlamydia infection, and endometrial carcinoma are significant conditions, they do not have a direct, established link to DES exposure. Osteosarcoma is more commonly seen in adolescents and young adults and is not associated with hormonal exposure in utero. Chlamydia infection is a sexually transmitted infection unrelated to in utero exposures. Endometrial carcinoma, although influenced by estrogen, has not been linked specifically to DES in the same way that clear