Advanced Bronchoscopic Techniques for Diagnosis of Peripheral Pulmonary Lesions

The number of newly diagnosed lung cancers will be greater than 200,000 in 2008 (1). As many as 25% to 30% of these will present as peripheral lesion (2). When a peripheral lesion is initially identified, the pretest probability of lung cancer should be assessed. This estimate of the probability of lung cancer being present should be based on a careful history, physical exam, and review of CT images. Factors to focus on include the lesion’s size, morphology, type of opacity, and growth rate (3). However, to confirm a diagnosis, a tissue biopsy will frequently be required. The site of biopsy will depend on the clinical context. Often, the diagnostic workup answering the question whether a patient has cancer is occurring in parallel with the staging workup, which answers the question of the extent of cancer spread. A concurrent staging evaluation is usually warranted if the pretest probability of malignancy is high. In this way, diagnosis and staging can be provided with the least number of invasive procedures. Often this entails performing a biopsy at a site that would identify the greatest extent of disease. For example, biopsy of an enlarged lymph node may be more desirable than biopsy of a mass, since it may serve the dual purpose of diagnosis and staging. In other instances, biopsy of a peripheral lesion may be the best approach, especially if there is already evidence of metastatic disease elsewhere. In those instances in which biopsy of a peripheral lesion is warranted, it is useful to be familiar with a wide range of diagnostic techniques, since the best approach will often vary with the clinical context in a given patient. In this chapter, we will review specific techniques that target peripheral lesions, focusing on their diagnostic sensitivity, specificity, and complication rates.