UTILIZATION OF MOLECULAR-GENETICS IN THE DIFFERENTIATION BETWEEN ADRENAL-CORTICAL ADENOMAS AND CARCINOMAS

Distinction between benign adrenal cortical proliferative lesions and adrenal cortical carcinoma has been approached by a combination of his tological, immunohistochemical, and macroscopical parameters. Modern i maging studies allow detection of small adrenal cortical lesions that may be incorrectly diagnosed. Differentiation between benign and malig nant tumors of the adrenal cortex nas attempted by microdissection of nine cases of adrenal cortical hyperplasia, 10 cortical adenomas, and 18 adrenalcortical carcinomas with subsequent polymerase chain reactio n (PCR) amplification for loss of heterozygosity (LOH) of five microsa tellites of putative tumor suppressor gene loci: p53 gene (17p), the n euroblastoma candidate gene (Ip), the p16 gene (9p), the von Hippel Li ndau gene (3p), and the retinoblastoma gene (13q). None of the hyperpl astic lesions or cortical adenomas showed LOH of any of the gene marke rs used. Conversely, genetic changes were observed in 61% (11 of 18) o f the cases of carcinoma. Forty-four percent of the lesions showed LO for p53 (7 of 16). LOH of Ip, 3p, and 9p ic ere seen in 22%, 22%, and 26%, respectively LOH of the retinoblastoma gene was seen in 80% or fo ur of five of the informative cases studied. We conclude that LOH stud ies may be used to distinguish malignant from nonmalignant adrenal cor tical proliferations. Relative infrequency of LOH in 3p may furthermor e help to differentiate adrenal lesions from clear cell carcinomas of the kidney. Copyright (C) 1998 by W.B. Saunders Company.