We desperately need a more useful technique for sampling lung. Transtracheal wash is almost useless, and BAL is only slightly better when it comes to providing any type of useful information about pathogenesis, therapy or prognosis. Percutaneous tru cut biopsies have proven extremely useful in investigating equine lung disease, but everyone is very nervous about the risk of pneumothorax when using that technique in dogs or cats. It is so rarely done that I do not know if anyone has documented the actual risk.

At least in my experience (meaning my own cases and those of colleagues), our ability to accurately capture and interpret fine needle aspiration samples of lung masses is poor. The sensitivity of the technique is low, and lung tissue frequently undergoes dysplastic change that is essentially indistinguishable from epithelial malignancy. Beware any diagnosis of adenocarcinoma based upon lung aspiration cytology!