[Hirsutism: differential diagnosis].

Hirsutism is one of the manifestations of the hyperandrogenic syndromes. A practical approach consists of dividing the hyperandrogenic syndromes into virilizing and non-virilizing, in accordance to the presence or absence of virilization symptoms. A case of a patient with hirsutism and a high basal and post-ACTH stimulation concentration of 17-OHP is presented. The absence of virilization and of clinical history discarded as etiology the virilizing neoplasias and hyperthecose of the ovary. Among the causes of non-virilizing syndromes, the presence of the menstrual disturbance and hyperandrogenemia discarded idiopathic hirsutism. In accordance to the Consensus of Rotterdam, the diagnosis of polycystic ovary syndrome was considered. For to exclude the non classic form of congenital adrenal hyperplasia due to 21-hydroxylase deficiency, the patient was submitted to a short ACTH-(1-24) stimulation test. The 17-OHP concentrations after stimuli were 14 ng/dL, being that, in the dependence of the limit of considered cut-off, it would be compatible with this illness. Although the promoter region had not been studied, we can consider that this diagnosis was excluded through the sequencing of CYP21A2 gene, since mutation on the promoter region is a rare event.