RÉSUMÉ
Disorders of sexual differentiation are rare congenital conditions in which the chromosomal, anatomic or gonadal sex development is atypical. In some of these patients, chromosomal sex is inconsistent with phenotypic sex; in other cases, the phenotype is not classifiable as either male or female, resulting in a condition known as ambiguous genitalia. These are very complex cases in which diagnostic certainty is not always possible. A multidisciplinary team including geneticists, pediatricians, radiologists is certainly needed to approach these patients. We present the case of an 18-year-old boy with an XY karyotype, ambiguous genitalia, uterus and blind-ending vaginal pouch. The patient had not been previously diagnosed with a disorder of sex development. The patient underwent a panel of genetic analyses and diagnostic imaging investigations. Magnetic resonance imaging was decisive for the identification of the internal genital organs, especially the uterus. At the end of investigations, the patient was diagnosed with 46,XY disorder of sex development. Our purpose is to underline the role of imaging in the diagnosis and management of congenital disorders of sex differentiation.