Bronchioloalveolar carcinoma in small pulmonary nodules: clinical relevance.

Increased use of chest computed tomography (CT) as well as improvements in CT resolution has led to increased detection of subcentimeter pulmonary nodules. Although the majority of these nodules are benign in etiology, a subset will harbor bronchioloalveolar carcinoma. The diagnosis of malignancy in this setting can be challenging to radiologists, surgeons, and occasionally pathologists as well. The challenge is compounded by a lack of knowledge about the natural course of these lesions--specifically, whether they represent life-threatening aggressive malignancies or indolent lesions of little or no consequence. Given the relative infrequency of these abnormalities, it will be essential to establish a sufficiently large database, to organize multi-institutional registries, and to collaborate on correlative studies. Only in this way will we be able to determine the clinical and molecular characteristics of these lesions and thus hopefully gain insight into their clinical relevance.