C-erbB-2 immunoexpression in parathyroid tumors and hyperplasias

Abstract

C-erbB-2 is a proto-oncogene previously implicated in the pathogenesis and prognosis of several human tumors. The authors investigated c-erbB-2 immunoexpression in parathyroid tumors and hyperplasias, and correlated its presence with the diagnosis and severity of the parathyroid lesions. One hundred two parathyroid tissues (28 adenomas, 12 primary hyperplasias, 57 secondary hyperplasias, and 5 carcinomatous tissues) were studied. Membrane c-erbB-2 (either in the cell membrane or on the border of pseudocysts) was absent in normal glands, and detected in 50% of the adenomas, 25% of the primary hyperplasias, 100% of the carcinomas, and 12 and 53% of the secondarily diffuse and nodular hyperplasias, respectively. C-erbB-2 expression was significantly lower in diffuse hyperplasias than in other parathyroid lesions (P<0.05). Cytoplasmic c-erbB-2 expression (restricted to oxyphil cells) was found in 50% of the normal tissues and in variable frequency in parathyroid lesions. Mean gland mass and intact parathyroid hormone levels were not significantly different according to c-erbB-2 immunodetection. Mean serum ionized calcium was higher in c-erbB-2-positive adenomas than in negative ones (P=0.006). In conclusion, c-erbB-2 protein is frequently detected in hyperproliferative conditions of the parathyroid, such as neoplasms and hyperplasias.