Infected Urachal Sinus with Urachal Cyst Following Umbilical Polypectomy in an Infant: A Case Report

Background

Urachal remnants are uncommon congenital anomalies resulting from incomplete obliteration of the embryonic urachus. An infected urachal sinus communicating with a urachal cyst is an unusual presentation and may be overlooked when persistent umbilical symptoms are attributed to superficial lesions. Case Presentation: A 1-year-old female infant presented with a 1-month history of recurrent purulent umbilical discharge, periumbilical erythema, and localised tenderness. She had undergone superficial umbilical polypectomy at 5 months of age and subsequently received repeated treatment for presumed stitch abscess and recurrent omphalitis. High-resolution ultrasonography demonstrated a 1.4-cm blind-ending sinus arising from the umbilicus and communicating with a thick-walled prevesical urachal cyst measuring 2.2 × 1.9 × 1.4 cm, with an estimated volume of 3.4 mL. No communication with the urinary bladder was identified. Exploratory infraumbilical laparotomy was undertaken, with complete excision of the sinus tract, urachal cyst, and fibrous remnant. Intraoperative pus culture yielded multidrug-resistant Proteus mirabilis. Antimicrobial therapy was subsequently adjusted to culture-directed intravenous meropenem with metronidazole. The postoperative course was uncomplicated, and follow-up at 2 and 6 weeks showed complete wound healing without recurrent discharge.