American Urological Association - Bladder Exstrophy
Home Education AUAUniversity Education Products & Resources Pathology for Urologists Urinary Bladder Histoanatomic Abnormalities/Malformations Bladder Exstrophy

Bladder Exstrophy

Image A

Image B

  • Congenital midline abdominal defect in which the bladder mucosa is everted "inside out" to the abdominal wall.
  • Other malformations may accompany, such as epispadias, cloacal exstrophy and cryptorchidism.
  • More common in males (male-to-female ratio 2:1).
  • Incidence is 1 in 30,000 births and risk for having a second child with the disease is 1 in 100 and if one parent has the disease is 1 in 70.
  • Urinary tract is open from urethral meatus to the umbilicus and the mucosa connects to the skin
    (image A).
  • Histology:
    • At birth, bladder mucosa is normal but gradually develops inflammation, ulceration and metaplasia.
    • With time, mucosa is replaced by metaplastic keratinizing squamous epithelium or intestinal type epithelium (image B).
  • Patients with long-standing exstrophy are at increased risk for cancer, particularly adenocarcinoma.
    • Risk diminished with early surgical intervention.