Chest scanogram of 23 year old male patient came with history of cough showing eliptical ares of increased opacity seen in the right upper lobe, medial end pointing towards the hilum and the lesion is sharply marginated.
Contrast enhanced CT scan showing non enhancing fluid attenuating lesion seen in the right upper lobe appears to be with in the dilated bronchi of posterior segment of right upper lobe. Can better appreciate on coronal reformatted image.
Bronchocele is commonly seen in congenital bronchial atresia, where there will be fluid accumulation in the bronchus distal to the atretic segment of bronchus. There are other rare causes for bronchocele like tumor obstructing the segmental bronchus, commonly carcinoids. The distal involved alveoli may show hypoplasia or a probable consequence of decreased ventilation and perfusion. These alveoli however remain open by collateral air drift occurring by the interalveolar pores of Kohn (air drift) or the bronchoalveolar channels of Lambert or the interbronchiolar channels with some amount of air trapping. Although radiograph is the first investigation to be done and suspected on it. The findings may show as described above in our case. Spiral CT is the examination of choice, not only to show all the components of the anomaly and to estimate the extent of air trapping but also for ruling out differential diagnosis such as bronchogenic cyst, bronchiectasis, aspergillosis, completely thrombosed arteriovenous malformation or pulmonary aneurysms and tumors.