Infant with Umbilical Fistula and Greenish Discharge: Diagnosis?

Introduction: The omphalomesenteric duct (OMD) is an embryologic communication between the yolk sac and the primitive midgut, which usually obliterates between the 5th and 9th week of gestation. In cases where involution is not complete, OMD remnants may persist with an estimated incidence of 0.6–4% in the general population. A variety of anomalies may occur such as Meckel`s diverticulum (67%) or more uncommon variants (e.g., fistulas).

Case report: A two-month-old female infant was admitted to the Emergency Department due to yellowish/greenish umbilical discharge, particularly noted whenever she was crying. No associated symptoms were reported. The available prenatal ultrasounds were described as normal. On physical examination, a small umbilical opening with discharge of enteric content was identified. Abdominal ultrasound showed a tubular structure extending from the umbilicus, which was suggestive of urachal/OMD remnant. Surgical excision was performed and histopathological examination confirmed a patent OMD with ectopic gastric mucosa.

Conclusion: In this case report, the presence of an umbilical fistula with discharge of enteric content suggested a patent OMD. Ultrasound examination was useful to support our clinical suspicion and to evaluate possible complications. Definitive diagnosis remains intraoperative and histopathological. Ectopic gastric mucosa in OMD remnants is particularly reported in symptomatic cases since gastric acid may produce inflammation and ulceration; these findings were not observed in our patient. Surgical excision is the treatment of choice, so recognition of suggestive signs is of utmost importance for early referral from general pediatrics to pediatric surgery.