Respiratory Exfoliative Cytology

The respiratory tract is comprised of upper and lower airways. The upper airway extends from the sinonasal tract to the larynx, and the lower tract extends from the trachea to the lungs. Although all sites are amenable to cytological sampling, the lower tract is usually the target for the detection of infections, benign lesions, and neoplastic processes. Various sampling techniques are utilized, occasionally with the use of concurrent needle core biopsies (NCB). In this chapter only the lower respiratory tract will be addressed.