Loss of Rb expression in an ACTH-secreting pituitary carcinoma.
Little is known about the molecular mechanisms of tumor progression in the pituitary. However, animal studies suggest that the Rb gene may be involved in the development of pituitary carcinoma. Pathologic examination of a pituitary tumor that included both benign and malignant components provided insight into this mechanism. Both benign and malignant tumors were immunoreactive for ACTH. The benign adenoma showed strong nuclear immunoreactivity for Rb, however, both the adjacent sellar carcinoma and its metastases were Rb-negative. This study suggests that loss of Rb may in some cases be important in the progression of pituitary adenoma to carcinoma.
Hinton
D R
DR
Department of Pathology, University of Southern California School of Medicine, Los Angeles 90033, USA.
Hahn
J A
JA
Weiss
M H
MH
Couldwell
W T
WT
D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology; D003480:Cushing Syndrome / Q000378:metabolism* / Q000473:pathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D010911:Pituitary Neoplasms / Q000378:metabolism* / Q000473:pathology; D016160:Retinoblastoma Protein / Q000378:metabolism*
D009363:Neoplasm Proteins; D016160:Retinoblastoma Protein; D000324:Adrenocorticotropic Hormone