“Not all bullae are synonymous with COPD”—a rare congenital anomaly described

Abstract

Hyperlucent areas with thin walls and absent vascular markings in chest X ray are described as radiological findings of a bullae. We present the case of an adult male referred for coronary revascularisation and bullectomy in the right lung. A non-smoker, without any significant past medical history, made us think of bronchial atresia. He was planned for coronary artery bypass grafting with close follow-up of lung anomaly. Clinicians should be aware of this entity in non-smokers with unilateral bullous lesion and calcification as other close clinical differentials warrant aggressive medical management.

Introduction

Bronchial atresia is a rare congenital developmental anomaly of the bronchus resulting in focal interruption at lobar, segmental or subsegmental level [1]. This results in mucous impaction and hyperinflation of the distal lung parenchyma by collateral ventilation through the pores of Kohn. Progressive parenchymal inflation results in bullous malformation and can finally lead to pneumothorax or recurrent lung infections due to inspissated mucus. The surrounding lung parenchyma becomes compressed and can get damaged in the long term. Most of these are detected incidentally in adulthood during evaluation for other purposes.

Case report

A 62-year-old male, non-smoker was evaluated for coronary artery disease and right lung pathology associated with shortness of breath. A preoperative chest X ray showed bullous lesions in the right upper lobe with calcified nodules (Fig. 1). On detailed enquiry, he denied past history of tuberculosis, exposure to any narcotic abuse, toxic fumes or recurrent attacks of pneumonia. A high-resolution computed tomography of the chest revealed areas of panacinar emphysema with bullae, air trapping, bronchoceles and calcification in the right lung (Figs. 2a, b). A fibre-optic bronchoscopy was performed, visualising patent lobar and segmental bronchi with non-visualisation of subsegmental bronchi in the right upper lobe. The clinico-radiological picture fits well with congenital bronchial atresia. Considering a good preoperative spirometry and paucity of symptoms (pneumothorax/recurrent chest infections) he was planned for a coronary revascularisation alone. It was decided to keep him in close follow-up to detect any progression in pulmonary disease.

Fig. 1.

Plain X ray of the chest showing bullous lesions in right upper lobe

Fig. 2.

a, b HRCT thorax-RT upper lobe cavity, air trapping, mucocele and calcification within bronchi

Discussion

Bronchial atresia is a rare developmental lung bud anomaly which is more of a radiological than a clinical diagnosis. Computed tomography findings of mucoceles with bronchial obliteration and distal emphysematous changes are typical in bronchial atresia. This coupled with a bronchoscopic identification of blind-ending lobar, segmental or subsegmental bronchus definitely clinches the diagnosis. Bronchoscopy is essentially important to exclude any obstructing intraluminal pathology which can lead to similar radiological findings. As the bronchial pattern and parenchymal development are essentially normal, insults in intrauterine vascular supply to the bronchus is proposed to be the causal factor for bronchial atresia [2]. Although believed to be congenital in origin, the causes for secondary bronchial atresia have been proposed by Raynor et al. [3] as mucosal hypertrophy, twisting of the bronchus or extrinsic compression by abnormal vasculature.

As bronchial atresia is mostly a benign entity without serious complications, awareness about this clinical picture is essential for practising physicians. In a tuberculosis high-prevalence place like ours, patients present with chronic respiratory symptoms and constitutional symptoms. The chest skiagram showing calcification and fibrotic bands may be misdiagnosed as untreated post-tuberculous sequelae and given unnecessary antituberculous drugs in symptomatic. Defect in vascularisation can lead to a radiological picture of oligaemia mimicking pulmonary thromboembolic disease [4]. It is essential to differentiate the two as management strategies that vary greatly. This case is reported to make cardiothoracic surgeons aware of such a clinical entity which may be incidentally detected in cardiac patients during evaluation to avoid unnecessary treatment.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Informed consent

An informed consent was obtained from the patient to publish the imaging pictures, although the patient’s identity was not revealed.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.