Immunohistochemical Profile of Tamoxifen-Related Uterine Adenosarcomas

Abstract

Abstract Background: Breast cancer is one of the most common cancers in women. Many patients are treated with tamoxifen therapy after diagnosis for 5 years. Cases: In this article, we present 3 patients who developed uterine adenosarcoma with rhabdomyosarcoma overgrowth following a history of breast cancer treated with tamoxifen for at least 5 years. All patients had completely staged stage IA adenosarcoma. All 3 tumors had the same distinct immunohistochemical staining pattern: vascular endothelial growth factor strongly positive, c-kit (CD117) weakly positive, nonspecific muscle actin strongly positive, smooth muscle actin negative, estrogen-receptor negative, and progesterone-receptor negative. Conclusions: This staining may be an identifying set of features for adenosarcomas with rhabomyosarcomatous overgrowth related to tamoxifen therapy. Uterine adenosarcoma with rhabdomyosarcoma overgrowth may be associated with previous tamoxifen treatment for breast cancer and has a very specific staining pattern...