ABSTRACT
The urachus is a normal embryonic remnant of the primitive dome. It generally exists as a fibrous cord extending from the dome of the bladder to the umbilicus. Disorders of the urachus are developed as a result of its incomplete regression. The urachal cyst is the most common urachal anomaly, and is usually asymptomatic in infancy and childhood. However, when the cysts are large or accompanied with secondary infection, they may be detected in its early stage. A sonography or CT scan may be helpful to confirm the diagnosis of urachal cyst. The managements of infected urachal cyst are varied from simple drainage to radical excision. Here, we report an unusual case of urachal cyst infection that occurred during corticosteroids therapy in a girl with IgA nephropathy.