Cohort 2: Mitotane-naïve patients with newly diagnosis of ACC associated with Cushing's syndrome not amenable to surgical resection with radical intent will be treated with single agent AA for 4 weeks followed by AA + Mitotane +/- first-line chemotherapy. In this cohort, AA in association with Mitotane will be administered for 3 months. If the primary endpoint is obtained before 1 month (i.e. 2 or 3 weeks from Abiraterone start), then Mitotane +/- chemotherapy can be started upon the clinician's decision.