ABSTRACT
There are three abnormal anatomical and bronchial tree arrangements:
morphologically right lungs)
Right isomerism may be associated with asplenia (Ivemark’s syndrome) and left isomerism with polysplenia.101 Both left and right isomerism may be associated with malrotation of abdominal viscera and congenital heart disease.44,101 The morphology of the bronchial tree is defined as the length of the main bronchus before the take-off of the upper lobe bronchus, the relation between the pulmonary artery and the upper lobe bronchus and the number of lobes in the lungs.26,44,101,166 Atrial situs and bronchial situs are normally identical.26 Left bronchial isomerism with normal atrial arrangement is extremely rare, but has been described as presenting with steroidresistance airflow obstruction.22
