Figure 5b. Localized bronchioloalveolar carcinoma in a 63-year-old woman. (a) Thin-section CT image obtained at the level of the right upper anterior segmental bronchus shows a 10-mm well-defined nodular ground-glass opacity without a solid component in the lower lobe of the right lung. Note the presence of pulmonary vessels in the lesion. (b) Photomicrograph of a histologic specimen (original magnification, x100; hematoxylin-eosin stain) shows replacement of the alveolar lining by neoplastic columnar epithelium, without evidence of stromal invasion.