Cisti dell'uraco

The urachal cysts are rare malformations (3:1 000 000) of the urachal remnants and are caused by unsuccessfully partial or total obliteration of the urachal duct connecting the posterior side of umbilicus to the bladder. From the embryological point of view, the urachus is a tubular structure, which connects the bladder with allantois at the umbilicus level. This structure normally regresses and becomes a fibro-muscular structure. The exfoliation or degenerative process in the urachal duct can cause developmental anomalies, responsible for complications in pediatric age. Most urachal cysts remain asymptomatic and are discovered by chance during ultrasound or radiological investigation for other diseases or as autoptic findings. They become symptomatic only if they are infected: they appear as an abdominal mass (47%), peri-umbilical erythema with exudation (41%) or with urinary symptoms (44%). These manifestations can appear alone or associated. The suppurate cysts, rare in the prepuberal age, can be responsible for acute abdomen and present some problems in the differential diagnosis with the more common acute appendicitis or Meckel's diverticulitis; infact they show localised pain in the right iliac fossa. In infancy, they can become infected and break off posteriorly in the peritoneal cavity, causing a clinical picture of generalised or more frequently localized peritonitis. The clinical cases personally observed are presented and the diagnosis and treatment discussed