An unusual presentation of an infected urachal cyst. Review of urachal anomalies.

An infected urachal cyst classically presents with a tender lower midline abdominal mass and systemic signs of infection, including fever, malaise, and leukocytosis. At times, the findings may be clinically confused with those of acute appendicitis, Meckel's diverticulitis, or peritonitis. Sonography aids in differentiating these entities by identifying the localized cystic mass containing debris, located anteriorly in the low mid-abdomen, extending from the region of the bladder to the umbilicus. We present an unusual case of an infected urachal cyst in a 6-year-old boy who presented with lower abdominal pain, fever, intermittent diarrhea, polyuria and dysuria, a firm, fixed left lower quadrant tender mass, and an elevated white blood cell count.