Cushing's syndrome induced by hypersecretion of cortisol from only one of bilateral adrenocortical tumors

A case of Cushing's syndrome induced by the unilateral (right side) dominance of cortisol secretion in the face of bilateral adrenal tumors is reported. The adrenal tumor resected on the right side was a so-called black adenoma and histologically without any findings of nodular hyperplasia. After resection of the adrenal adenoma, no findings of cortisol hypersecretion from the remaining adrenal tumor on the left side were observed until the present, suggesting that the tumor of the left adrenal gland is a nonfunctioning adenoma. These data imply that the adrenal adenomas have primarily developed from the adrenal gland itself, rather than from micronodular hyperplasia by corticotropin stimulation, and that one of these tumors produces excess hormones initially by corticotropin stimulation, but the other remains in cell proliferation.