Some variations in lymphatic drainage of selected bronchopulmonary segments in human lungs

Interest in the role of the pulmonary lymphatic system in the pathophysiology of pulmonary and systemic diseases induced us to carry out anatomical research on the lung lymphatic system in the Polish population. The aim of the study was to evaluate whether lymphatic vessels respect bronchopulmonary segment borders and to determine how often lymphatic vessels run to nodes of another lymphatic region. A block of organs comprising the lungs with the trachea, larynx and tongue, the heart and esophagus was removed from the cadavers at autopsy. The research involved 96 lungs (48 left and 48 right), which were taken from 31 male and 17 female cadavers. The lymphatic vessels were visualized at the mediastinal and interlobar surface of the lung by visual inspection. These vessels were then cannulated and injected with drawing ink. Next, the course of a lymphatic vessel was checked to see whether it was compatible with the bronchopulmonary segments or lobar borders. The first lymph node to become ink-colored via injection was dissected and histologically examined. A total of 135 images of lymphatic vessels (63 in the left lungs and 72 in the right lung) running on the mediastinal or interlobar surface of the lung were evaluated. In all, 12 out of 135 vessels (8.9%) were observed to cross the border of the segment (6/12 vessels) or the border of the lobe (6/12 vessels). We found 10/135 vessels (7.4%) running to the lymph nodes of another lymphatic region.