Treatment of adrenal cortical carcinoma with mitotane: outcome and complications

Adrenal cortical carcinoma is a rare tumour with a poor prognosis. We report a patient with metastatic adrenal cortical carcinoma who responded dramatically to Mitotane (o,p'-DDD). Unlike previous reports of metastatic adrenal cortical carcinoma in which complete remission was obtained with high dose Mitotane treatment, the dose of Mitotane used in this patient was low. However, she developed unusual side-effects such as hyperpigmentation, low plasma cortisol and high adrenocorticotropic (ACTH) levels. The side effects closely resemble those in Nelson's syndrome and were reversed by cortisone replacement. The mechanism of actions of Mitotane is discussed with emphasis on its effect on corticosteroid metabolism.