title: Differentiating Swyer syndrome and complete androgen insensitivity syndrome: a diagnostic dilemma.
abstract: BACKGROUND
  Swyer syndrome and complete androgen insensitivity syndrome are disorders of sex development in which patients present a female phenotype and 46,XY karyotype.
  
  
  METHODS
  The authors present a case report of an 18-year-old patient with primary amenorrhea and delayed puberty. The karyotype was 46,XY. No mutations of sex-determining region Y gene and androgen receptor genes were identified, and imaging methods failed to show müllerian structures. A diagnosis of complete androgen insensitivity syndrome was presumed, but after hormonal replacement therapy was started a "hidden" uterus developed, leading to the definite diagnosis of Swyer syndrome.
  
  
  CONCLUSIONS
  The diagnosis of Swyer syndrome can be challenging, because visualization of müllerian structures is sometimes difficult and analysis of genetic mutations is not helpful in the majority of cases.
authors.affiliation: Department of Gynecology, Maternidade Bissaya Barreto, Centro Hospitalar e Universitário de Coimbra, Portugal.
authors.forename: Elsa
authors.initials: E
authors.lastname: Nunes
authors.affiliation: Department of Gynecology, Maternidade Bissaya Barreto, Centro Hospitalar e Universitário de Coimbra, Portugal.
authors.forename: Carla
authors.initials: C
authors.lastname: Rodrigues
authors.affiliation: Department of Gynecology, Maternidade Bissaya Barreto, Centro Hospitalar e Universitário de Coimbra, Portugal.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Geraldes
authors.affiliation: Department of Gynecology, Maternidade Bissaya Barreto, Centro Hospitalar e Universitário de Coimbra, Portugal.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Aguas
mesh_terms: D000293:Adolescent; D000568:Amenorrhea / Q000209:etiology; D013734:Androgen-Insensitivity Syndrome / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006061:Gonadal Dysgenesis, 46,XY / Q000150:complications / Q000175:diagnosis* / Q000628:therapy; D020249:Hormone Replacement Therapy; D006801:Humans; D008297:Male; D010053:Ovary / Q000002:abnormalities; D011628:Puberty, Delayed / Q000209:etiology; D014599:Uterus / Q000002:abnormalities
keywords: Gonadal dysgenesis; Primary amenorrhea; Swyer syndrome