Abstract

We present an unusual case with bilateral testicular Leydig cell tumors displaying extraadrenal expression of steroid 21-hydroxylase and 11 beta-hydroxylase. Histological examination of a 38-yr-old man infertile due to azoospermia showed him to have bilateral testicular Leydig cell tumors. The in vitro steroidogenic potential of the tumors and their adjacent testicular tissue was evaluated using organ culture. Tumor tissue was found to secrete deoxycorticosterone (DOC), corticosterone (B) and cortisol, which are not produced in normal adult testis, into the medium, while testicular tissue adjacent to the tumors secreted a small amount of DOC and B. Northern blot analysis with cytochrome P-450C21 complementary DNA (cDNA) and P-45011 beta cDNA as probes revealed that the tumor contained a considerable amount of mRNA for P-450C21 and P-45011 beta, while the MRNAs were not detected in the testicular tissues adjacent to the tumors. It is suggested that the high local levels of estrogen and/or progesterone within the Leydig cell tumors and their adjacent testicular tissues induced extraadrenal expression of steroid 21-hydroxylase and 11 beta-hydroxylase by the tumors and their adjacent testicular tissues.