Immunohistochemical expression of estrogen receptors in chondrosarcomas and enchondromas.

Immunohistochemical expression of estrogen receptors alpha and beta was studied in chondrosarcomas and enchondromas and was correlated with chondrosarcoma grade, type, and dedifferentiation. Estrogen receptor alpha was studied in 37 chondrosarcomas, 10 enchondromas, and 2 extraskeletal myxoid chondrosarcomas. Estrogen receptor beta was studied in 23 chondrosarcomas, 6 enchondromas, and 2 extraskeletal myxoid chondrosarcomas. Ventana prediluted monoclonal anti-ER alpha (clone 6F11) and Biogenex prediluted polyclonal anti-ER beta were used on the Ventana ES autostainer and BenchMark XT IHC/ISH, respectively. Percent of cell staining and intensity (+, ++, or +++) was evaluated. Overall, 61% of conventional chondrosarcoma and 60% of enchondroma were positive for estrogen receptor alpha. Low-grade chondrosarcoma expressed estrogen receptor alpha more frequently than high-grade chondrosarcoma (P<or=.001). Extraskeletal myxoid chondrosarcomas expressed estrogen receptor alpha; it was not expressed in dedifferentiated chondrosarcoma. Overall, 89% of conventional chondrosarcomas and 83% of enchondromas were positive for estrogen receptor beta. Low-grade chondrosarcomas expressed estrogen receptor beta more frequently than high-grade chondrosarcomas (P<or=.05). Extraskeletal myxoid chondrosarcomas expressed estrogen receptor beta; it was frequently lost in dedifferentiated chondrosarcoma.