cytology test

I had a cytology test today and they found blood in my bronchus tree, what would cause this

[Dr Santos]

Hi,
How are you? Cytologic evaluation of the bronchial tree is the analysis of cells collected to determine what the cells look like, and how they form and function. Your result  may suggest blood leaks from blood vessels in the bronchial tree, may have occurred spontaneously or due to pulmonary issues present. It is best that you discuss the results with your doctor for proper evaluation. Your medical history and symptoms present are important considerations in determining the underlying cause. Take care and do keep us posted.