Infraumbilical Abscess Due to Meckel's Diverticulum Co-occurring With a Urachal Remnant: A Case Report

Meckel's diverticulum is the most common congenital anomaly of the gastrointestinal tract, and urachal remnants, another congenital anomaly, arise from the incomplete involution of the fetal urachus. Although both conditions have been studied extensively, their co-occurrence is rare and may complicate the diagnosis, particularly if an infection is present. A 22-month-old male patient presenting with abdominal pain was found to have an infraumbilical abscess in the preperitoneal space. Initial imaging studies demonstrated a urachal abscess extending toward the bladder. Following antibiotic therapy, elective surgery was performed collaboratively by pediatric urologists and pediatric surgeons to manage a concurrent inguinal hernia. Intraoperatively, Meckel's diverticulum with a mesenteric band connected to the umbilicus was identified in addition to a urachal cyst, prompting an en bloc resection of the abscess, urachal cyst, and Meckel's diverticulum. Histopathological analysis demonstrated that the abscess most likely originated in the omphalomesenteric remnant rather than the urachal remnant. Infraumbilical abscesses can originate in omphalomesenteric duct remnants as well as urachal remnants. Clinicians should consider the possibility of the co-occurrence of multiple congenital anomalies in a patient with an infraumbilical abscess to ensure complete surgical treatment.