Tracheal Bronchus: An Unusual Cause of Recurrent Lower Respiratory Tract Infection.

A 14-month-old male child presented with a history of recurrent pneumonia of the right upper lobe of the lung. Computed tomography scan showed an accessory bronchus proximal to the carina on the right side with collapse consolidation of the lobe. Copyright:

INTRODUCTION

Tracheal bronchus is an unusual congenital anomaly in which the right upper lobe of the lung has its origin in the lateral wall of the trachea rather than distal to the carina.[1] It is also known as “pig bronchus” or “bronchus suis” as it is a normal anatomical finding in pigs. The term pig bronchus is used when the entire upper lobe is supplied by a separate bronchus.[2]

CASE REPORT

A 14-month-old male child was brought by parents with chief complaints of cough with expectoration, fever with chills, and difficulty in breathing for the past 3–4 days. The respiratory system examination revealed coarse crepitations in the right infraclavicular area and infrascapular area. The chest X-ray revealed heterogeneous infiltrate and consolidation of the right upper lobe. The patient had four episodes of similar complaints in the past since the age of 1 month, for which the patient was admitted and was given medical management. Each episode responded to medical management only to recur after a period of 4–6 weeks.

In view of the recurrent nature of disease, a decision was taken to do computed tomography (CT) scan of the chest. Contrast enhanced CT of the chest revealed a presence of an accessory bronchus arising about 3 mm proximal to the carina on the right side [Figure 1]. There was associated collapse consolidation of the right upper lobe. With all the investigations and clinical correlation, the diagnosis of tracheal bronchus was made, which was responsible for multiple recurrent episodes of lower respiratory tract infection in this patient.

Figure 1

Plain computed tomography scan of the patient showing an accessory bronchus branching out from the lateral wall of the trachea on the right side (black arrow pointing toward the accessory bronchus)

The tracheal bronchus was resected surgically with the corresponding lobe of the lung supplied by it by the pediatric surgeons and was sent for histopathological examination. The histopathogical examination revealed polymorphonuclear cell inflammation of lung parenchyma with fibrin exudates. The patient responded very well with the surgical management and is on a regular follow-up for the last 1 year with no further episodes of lower respiratory tract infections.

DISCUSSION

The tracheal bronchus is an aberrant, accessory, or ectopic bronchial branching occurring from lateral aspect of the trachea on the right side. It occurs as a result of an additional tracheal outgrowth early in embryonic life. Tracheal bronchus was first described by Sandifort in 1785.[1] Tracheal bronchus is usually asymptomatic. CT scan of the chest is the imaging investigation of choice and is recommended in every case suspected to have tracheal bronchus. It can tell in three dimensions the pathology, confirmation of diagnosis, and the type and any additional pathology if present in the adjacent lung parenchyma.

In patients with recurrent Right upper lobe (RUL) disease and a tracheal bronchus, the surgical resection of the aberrant bronchus, as well as the lobe it supplies, is the treatment of choice.[3] Asymptomatic cases can be observed on a regular follow-up.

CONCLUSION

Tracheal bronchus can be a cause of recurrent lower respiratory tract infections in immunocompetent individuals requiring surgical management in symptomatic cases.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the parents have given their consent for images and other clinical information to be reported in the journal. The parents understand that names and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.