대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Imaging Findings

Initial chest radiograph shows homogenous air-space consolidation with air-bronchogram in the right upper lung zone and multiple small nodular opacities in the both lung fields. Follow-up chest radiograph shows increased extent of air-space consolidation. CT scans reveals that there is no obstructive lesion in the right upper lobe bronchus. The consolidation is present in the right upper lobe and right middle lobe. There are also numerous patchy and nodular lesions, some of which have internal air densities. The patient expectorated large amount of sputum upto one litter per day, which was mucoid in nature with bubble-like appearance, so called a feature of bronchorrhea. The diagnosis was confirmed by bronchoscopy with BAL and cytologic examination.

Discussion

Bronchioloalveolar carcinoma represents 1.5%-6.5% of all primary pulmonary neoplasms (1). Bronchorrhea (white mucoid or watery expectoration) is unusual and a late manifestation. Bronchioloalveolar carcinoma tends to spread through the airways, but lymphogenous and hematogenous dissemination may occur in 50%-60% of cases (2). Bronchioloalveolar carcinoma appears radiographically as a single nodule, segmental or lobar consolidation, or diffuse nodules (3). The lobar consolidative form may demonstrate the CT angiogram and open bronchus signs. The diffuse nodular form appears as multiple nodules or areas of ground-glass atteunuation or consolidation.
Bubblelike areas of low attenuation (pseudocavitation) are observed more frequently with bronchioloalveolar carcinoma (50% of cases) than with other malignant lesions (4). Bubblelike areas of low attenuation within the lesion are due to patent small airways within the nodule or distended alveolar spaces within papillary regions of tumor ingrowth. Because the tumor proliferates along the walls of the alveolus without disrupting the overall lung architecture, pseudocavitation may also occur when bronchioloalveolar carcinoma develops adjacent to an area of preexisting cystic change.
The multinocular form (seen radiographically in 27% of cases) manifests as multiple, bilateral, well-circumscribed nodules on radiographs. The CT appearances of multinodular bronchioloalveolar carcinoma are diverse and include poorly or well-defined nodules, multiple cavitary nodules, and multiple poorly defined areas of ground-glass attenuation or consolidation (5).

Reference

1. Barsky SH, Cameron R, Osann KE, Tomita D, Holmes EC. Rising incidence of bronchioloalveolar lung carcinoma and its unique clinicopathologic features. Cancer 1994; 73: 1163-1170
2. Greenberg SD, Smith MN, Spjut HJ. Bronchioloalveolar carcinoma: cell of origin. Am J Clin Pathol 1975; 63:153-167
3. Lee KS, Kim Y, Han J, Ko EJ, Park CK, Primack SL. Bronchioloalveolar carcinoma: clinical, histopathologic, and radiologic findings. Radiographics 1997; 17: 1345-1357
4. Zwirewich CV, Vedal S, Miller RR, Muller NL. Solitary pulmonary nodule: high-resolution CT and radiographic-pathologic correlation. Radiology 1991; 179: 469-476
5. Zwirewich CV, Miller RR, Muller NL. Multicentric adenocarcinoma of the lung: CT-pathologic correlation. Radiology 1990; 176: 185-190

Keywords

Lung, Malignant tumor,