Right-sided bronchial isomerism diagnosed in adulthood

This case report describes a diagnosis of right-sided isomerism and specifically right-sided bronchial isomerism in a patient who was being investigated for deteriorating bronchiectasis. Right-sided bronchial isomerism is a variation of the normal bronchial anatomy (situs solitus) consisting of a left lung that is identically configured at the bronchial and lobar level to the right. It is sometimes referred to as bilateral right lung and is usually associated with congenital asplenia and therefore impaired immunity with susceptibility to pneumococcal sepsis and cardiac abnormalities which may be severe and result in a high mortality in infancy.1 Ivemark syndrome (also known as right atrial isomerism) combines these associations with malrotation of the gut and a midline liver.2 Interestingly, left-sided isomerism is associated with polysplenia as well as midline liver, malrotation of the gut, partially anomalous pulmonary venous drainage and cardiac septal defects.3 To the best of our knowledge cases of right-sided isomerism are sufficiently rare in adulthood that there are only two other reports in the literature and only one of the patients had bronchial isomerism.4,5