Congenital broncho-esophageal fistula (BEF) is a rare disease (
1). It is usually diagnosed in infancy and commonly associated with esophageal atresia. Isolated BEF diagnosis may be delayed until adulthood due to the insidious onset of symptoms (
2,
5). According to Brambridge and Keith classification, broncho-esophageal fistulas are divided into four types including type 1 that is defined as a wide diverticulum with a fistula at the tip, type 2 that is a simple fistula, type 3 that is a fistula with a cyst, and type 4 that consists of a fistula with sequestration segment (
1). The present case was a missed case of type 2 BEF associated with TEF, EA, and skeletal anomalies diagnosed in childhood. The age of presentation and associated anomalies in the present case were unique compared to previously reported cases (
1,
6-
8). The clinical signs and symptoms of BEF are nonspecific, including coughing, chronic aspiration pneumonia, and hemoptysis (
2). Persistent respiratory symptoms following TEF repair is not an unusual presentation. Up to 50% of children with a history of esophageal atresia and TEF repair have recurrent or persistent respiratory symptoms. This is due to tracheomalacia, hyper airway reactivity, or repeated aspirations as a result of esophageal dysmotility or stricture, gastroesophageal reflux, or relapse of repaired TEF (
9). The most common cause of respiratory complications in patients undergoing prior TEF repair is GER (
10); however, other factors such as BEF must be considered. The upper gastrointestinal series with thickened water-soluble contrast agent is a sensitive and available diagnostic approach. The traditional pull-back technique in which the distal esophagus is first filled and then the esophageal catheter is pulled up to proximal portion may increase the diagnostic precision of the method (
11). However, contrast swallow study may fail to demonstrate the fistulous tract, as observed in the present case. Several reasons can account for this phenomenon. First, the length of the fistula may be short with a small diameter; therefore, the thick contrast material cannot pass through it. Second, since the track may have a sharp, upward angle from the esophagus, the contrast would not pass through the fistula as a result of gravity. Third, an esophageal flap may result in a check valve and close the fistulous track intermittently (
8). Bronchoscopy or endoscopy can also recognize the abnormal fistula between the tracheobronchial tree and esophagus. However, the detection of tracheal or bronchial opening in small fistulas can be challenging (
12). At our center, the demonstration of the fistula is facilitated by the injection of a small amount of methylene blue into the esophagus and the appearance of leakage via the fistulous tract in the tracheobronchial tree.