Multiple lutein cyst (MLC) and luteoma are two aspects of ovarian hyperplasia induced by high levels of human chorionic gonadotrophin (HCG). Using a case report of MLC, the authors compare it with luteoma (the anatomoclinical and pathogenic data). Luteoma are more frequent with multipara, whereas MLC are more often seen with paucipara. Maternal virilization can occur in both cases but MLC does not seem to be responsible for fetal virilization. The fetus could be protected by the placenta, thanks to increased aromatase activity and sex binding globulin production. MLC and luteoma are usually found by chance. The pathology must be known, because of their spontaneous regression after delivery. So, the attitude will be conservative under the control of biopsies.