[Pituitary melanocytoma mimicking an adenoma].

A 62-year-old woman was referred for a pituitary tumour diagnosed because of a chronic asthenia and visual disorders. Cerebral MRI showed a pituitary tumour compressing the optic chiasm and enhanced after gadolinium injection. Biological findings showed panhypopituitarism and hyperprolactinemia. The diagnostic of pituitary macro-adenoma was performed and the patient was treated with hormone replacement therapy and dopaminergic agonist. Six months later, she presented visual disorders worsening leading to surgical excision. The diagnosis of pituitary melanocytoma was performed after anatomo-clinical confrontation. Post-operative radiation was done.