[A case of infected urachal cyst in an 8-year-old boy].

An 8-year-old boy with infected urachal cyst presenting with macroscopic hematuria, pain on urination and high fever attack is reported. He had recurrent episodes of cystitis. At admission, a quail-egg sized solid tumor was palpated in the midline of his lower abdomen. The urine was infected. Ultrasonographic examination revealed an oval tumor 2 x 2.7 cm in diameter at the dome of the bladder with a thin funicular structure running toward the umbilicus. Cystoscopy revealed a round tumor covered with hyperemic epithelia. Transurethral biopsy revealed no malignant lesions of the epithelia. Partial cystectomy with excision of the funicular urachal ligament was performed. The pathological findings were consistent with persistent urachus with chronic inflammation. We reviewed 210 cases of infected urachal cysts reported in the Japanese literature.