Clinical Profile:

A 10 day old baby, aboy, born at term, spontaneously through normal vaginal delivery was antenatally diagnosed to have dextroposition of heart.

The baby had increased respiratory activity.

On auscultation, the apex of the heart was on the right, with decreased breath sounds on the right.

Radiological findings:

Frontal chest radiograph shows air space opacification in the right mid and lower zones. the proximal order bonchi are dilated. There is marked loss of volume with shift of mediastinum to the right . The left lung is hyperinflated with increased vascular markings Figure A) , Importantly, there is aeration in the peripheral portions of the right hemithorax.

A contrast enhanced CT confirmed the radiographic findings of right lung collapse and consolidation with mediastinal shift to right. (Figure B below)

Both lungs had normal arterial supply and venous drainage (not shown)

The trachea continued as the left main bronchus. (Figure C)

•The right bronchus appeared to come off the esophagus and supplied the entire right lung.(Figure D)

Esophagogram (Figure E & F) performed with diluted barium demonstrates the origin of right bronchus from the retrocardiac esophagus, opacifying the right bronchial tree.

A diagnosis of esophageal bronchus supplying the right lung was made.

On retrospective observation of the chest radiograph (Figure A), the carina and right main bronchus are not seen.

Final diagnosis :

Esophageal Lung

Treatment:

Through a right thoracotomy, the abnormal bronchus was traced to the esophagus and ligated off.

The patient was briefly cared for in the NICU for lactic acidosis and discharged after treatment.

Discussion :

•Abnormal communications of the foregut with the tracheobronchial tree are a part of the spectrum of congenital bronchopulmonary foregut malformations (BPFM) along with oesophageal atresias, pulmonary sequestrations, duplication cysts and diverticuli of the gastrointestinal and pulmonary tracts [1].

•An accessory lung bud originating from the primitive oesophagus caudal to the normal lung bud is considered to lead to the formation of BPFM. The pedicle of this accessory lung bud commonly involutes.

•Failure of involution of the pedicle results in communication between the foregut and the lung parenchyma forming the subgroup of congenital communicating foregut malformations BPFM.[2]

•Another theory proposed by Srikanth et all classifies communicating BPFM into four groups based on the type of communication and associated anomalies.[3] [4]

•Group 1 : Sequestered lung (Complete : 1A, Partial :1B) with esophageal atresia and tracheoesophageal fistula

•Group 2: Lung sequestration communicating with the lower esophagus.

•Group 3: A A segment of lung communicating with the foregut.

•Group 4: A portion of normal bronchial segment communicating with the esophagus.

THis patient patient falls in Group 4, where the entire lung was aerated by the right main bronchus which originated from the lower esophagus.

The term esophageal lung is used when a main bronchus arising directly from the oesophagus aerates the entire lung. It is typically the right bronchus owing to developmental proximity of the oesophagus, which is to the right of the trachea. [5]

The clinical severity of an esophageal bronchus depends on the amount of lung parenchyma it aerates and the presence of associated anomalies.[6] Patients usually present with recurrent pulmonary infections

The radiologist plays an important role in identifying this communication on a CT scan - usually performed for the evaluation of lung collapse. The differential diagnosis in this case includes lung sequestration which is excluded in view of absence of abnormal systemic arterial supply and also as the entire lung was involved.

Treatment consists of either resection of the esophageal lung or lobe. If the vascular supply of the lung is normal which is confirmed on CT bronchial reconstruction with anastomosis to the esophageal lung can be done.

Communicating bronchopulmonary foregut malformations are a rare group of congenital disorders.

It is important to identify the normal bronchial anatomy in a CT of the chest done for lung collapse. CECT of the chest is also useful in evaluating the vascular supply of the lung which helps in diagnosis and also directs treatment.

Patients with suspected sequestration should undergo an esophagram to rule out any foregut communication.

References :

1. Heithoff KB, Sane SM, Williams HJ, Jarvis CJ, Carter J, Kane P, Brennom W. Bronchopulmonary foregut malformations. A unifying etiological concept. American Journal of Roentgenology. 1976 Jan 1;126(1):46-55.

2. Leithiser Jr RE, Capitanio MA, Macpherson RI, Wood BP. " Communicating" bronchopulmonary foregut malformations. American journal of roentgenology. 1986 Feb 1;146(2):227-31.

3. Srikanth MS, Ford EG, Stanley P, Mahour GH. Communicating bronchopulmonary foregut malformations: classification and embryogenesis. Journal of pediatric surgery. 1992 Jun 1;27(6):732-6.

4. Seetharaman C, George VC, Daniel JR, Davis VS, Koshy RM. Case report: Communicating bronchopulmonary foregut malformation type III (esophageal lobe). Indian J Radiol Imaging 2007;17:264-6

5. Sur A, Sardar SK, Paria A. Left Sided Oesophageal Lung: A Diagnostic Challenge. Case reports in pediatrics. 2013;2013.

6. Benson JE, Olsen MM, Fletcher BD. A spectrum of bronchopulmonary anomalies associated with tracheoesophageal malformations. Pediatric radiology. 1985 Sep 1;15(6):377-80.

Acknowledgement:

We are grateful to the Department of Paediatric Surgery at out institution for providing the intraoperative images.