Congenital BOFs were first reported by Gibson in 1696, and again by Negus in 1929. This is a rare condition and most documented cases have been isolated case reports. The largest published series included  100 patients, 24 of whom were children. BOFs occur equally in male and female patients. Age of presentation is variable: the youngest patient was 9 days old while the oldest was an 83-year-old man. 
 Four types of congenital BOF are described. Type 1 has a wide-necked congenital diverticulum of the oesophagus, with an inflammatory fistula at the tip. Type 2 is the simplest, with a short track that runs from the oesophagus to the lobar or segmental bronchus. In type 3, a fistulous track connects the oesophagus to a cyst in the lobe that communicates with the bronchus. In type 4, the fistula communicates with a sequestered segment, which is identified by the presence of a branch of a systemic artery from the aorta. The latter, type 4, describes the fistula of our patient. 
 BOFs have either a congenital or an acquired cause. Congenital causes include isolated malformations or are in association with other anomalies such as bronchopulmonary sequestration, which is the most common. Acquired causes include infections (Mycobacterium tuberculosis, histoplasmosis, actinomycosis), trauma, ingestion of caustic materials or inhalation of a foreign body. Unlike in adults, most acquired causes are non-malignant in children. Acquired BOFs secondary to tuberculosis should always be considered, especially when symptoms occur in older children and the child resides in an area where TB is highly endemic, as was the case with our patient. Differentiating a congenital BOF from an acquired one is difficult, especially in the presence of advanced pulmonary disease. This is definitively diagnosed only on histological examination by the absence of surrounding inflammation, the absence of adherent lymph nodes and the presence of a mucosa and muscularis mucosa. 
 The most common location of BOFs is between the middle third of the oesophagus and the right lower lobe (41%), followed by the left lower lobe (21%), right main bronchus (18%), bronchus intermedius (10%), left main bronchus (6%), right middle lobe (2%) and right upper lobe (2%). 
 Symptoms of BOFs are insidious, occasionally beginning in childhood but rarely at birth. Symptoms are often not present until adulthood and even then are often intermittent. The duration of symptoms is variable and ranges between 6 months and 50 years before treatment is instituted. Symptoms include coughing, choking, haemoptysis and recurrent respiratory tract infections. The latter results in suppurative lung diseases such as lung abscesses, empyema and bronchiectasis, which can present with clubbing, basal crackles and pleural effusions. Some patients present with gastrointestinal symptoms such as dysphagia, epigastric discomfort and reflux caused by the stomach filling with air on expiration, although these are uncommon. Non-specific respiratory symptoms include coughing and frequent infections, or coughing when ingesting liquids precipitated by certain postures. 
 Possible reasons for the delay in the onset of symptoms include the presence of an oesophageal fold that obstructs the opening of the fistula, the presence of a membrane that ruptures or a fistulous tract that is directed upwards from the oesophagus, allowing gravity to assist spasms of the smooth muscle in the fistula wall. Occasionally, patients adapt to the symptoms. 
 Diagnosis is made by an upper gastrointestinal tract contrast study. Bronchoscopy and oesophagoscopy may demonstrate the orifice of the fistula, but it is usually small and recognisable only when the site is known. Infusing saline into the trachea with positive pressure  ventilation while observing for bubbles at the site of the fistula can aid in the diagnosis. In addition, instilling methylene blue or a nontoxic dye into the oesophagus during bronchoscopy or in the trachea during oesophagoscopy may also delineate the fistula. A CT scan or magnetic resonance imaging can reveal the fistula. 
 Definitive treatment is surgical closure of the fistula, with excision of the damaged lung segments. A further approach, if thoracotomy is not feasible, is obliteration of the oesophageal end of the fistula with silver nitrate, biologic glue or a Celastin tube. 
 This case describes an extremely rare and unusual cause of haemoptysis secondary to a type 4 congenital BOF. A congenital BOF should be suspected in patients with recurrent or persistent respiratory symptoms related to swallowing difficulties or choking in any age group or with unexplained suppurative lung diseases.