Abstract
To examine whether or not a part of human parathyroid adenomas have a malignant potential, 15 parathyroid tumors including 13 adenomas, 1 hyperplasia and 1 adenocarcinoma were studied for the amplification of the c-erbB2 proto-oncogene. Eleven adenomas of these tumors were also evaluated for the immunohistochemical expression of the c-erbB2 gene product. The amplification of the c-erbB2 proto-oncogene (2-fold or more greater than control) was recognized in 3 adenomas (23.1% of all adenomas) and 1 adenocarcinoma as compared to a pooled human normal placenta, which serves as control. Six out of 11 parathyroid adenomas (54.5%) revealed the immunohistochemical expression of the c-erbB2 gene product on the cell membrane and in the cytoplasm. Three adenomas (27.2%) showed the strongly positive (_??_) staining and the other 3 adenoma (27.2%) showed the weakly positive (+) staining. The 2 cases having the amplification of the c-erbB2 proto-oncogene also revealed the strongly positive staining. The c-erbB2 proto-oncogene, which has been reported to be amplified or expressed in some adenocarcinomas, might be associated with the initiation and progression of some parathyroid adenomas. The present findings might suggest that some parathyroid adenomas could have a malignant potential.
