Fluorescent histochemical demonstration of estrogen and progesterone binding in giant cell tumors of bone: preliminary observations.

Hormonal receptors of giant cell tumors (GCTs) have not been previously reported. Five cases of GCT of bone were analyzed for estrogen and progesterone binding. Frozen sections were studied by a histochemical method, using 17-beta-6-CMOBSA-FITC and 11-alpha-hydroxyprogesterone-HS-BSA-TMRITC. Cytoplasmic fluorescence with estradiol-BSA-FITC was seen in stromal cells of all five tumors; three also showed cytoplasmic staining with progesterone-BSA-TMRITC. No fluorescence was seen in the giant cells. Two cases were also analyzed by a dextran-coated charcoal cytosol assay. No estrogen or progesterone receptor was detected by cytosol assay. This study suggests that the estrogen and progesterone binding is present in GCT of bone, possible to low-affinity sites rather than high-affinity receptors. Further investigation of hormonal receptors of GCTs of bone is warranted.