대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

BAC (Bronchioloalveolar Carcinoma)

Radiologic Findings

CT scans shows multifocal patchy areas of confluent airspace consolidation and ground-glass attenuation in both lungs.
Air bronchograms are well visualized within the consolidations.
Some patchy nodules seem to be centrilobular in location.

Diffuse form of BAC (bronchioloalveolar carcinoma), malignant lymphoma, and active pulmonary tuberculosis can be considered in the pictures like these.

Brief Review

Bronchioloalveolar carcinoma is characterized pathologically by lepidic growth with preservation of lung architecture. The most frequent symptoms and signs in patients with bronchioloalveolar carcinoma include cough, sputum, shortness of breath, weight loss, hemoptysis, and fever. Bronchorrhea, once considered the clinical hallmark of this disease, is unusual and is a late manifestation seen only with diffuse bronchioloalveolar carcinoma (1, 2).

The radiologic manifestations of bronchioloalveolar carcinoma are diverse and include single or multiple pulmonary nodules, segmental or lobar consolidation and diffuse airspace disease. Alveolar filling disorders are usually seen in forms of segmental or lobar and diffuse airspace disease. The lobar consolidative form accounts for approximately 30% of all bronchioloalveolar carcinomas and corresponds to a mucinous histologic type. The airspace consolidation is caused by growth along the alveolar wall combined with secretion of mucin.

Production of copious amounts of mucin may result in expansion of the involved lobe, leading to bulging of interlobar fissures. The CT angiogram sign is caused by the homogeneous low attenuation of consolidation, which allows vessels to be clearly seen, particularly after intravenous administration of contrast material. The CT angiogram sign is nonspecific and may also be seen in lobar pneumonia, pulmonary lymphoma, extrinsic lipid pneumonia, pulmonary infarction, and pulmonary edema. According to recent report by Akira et al (3), diffuse bronchioloalveolar carcinoma can be classified into three patterns: ground-glass opacity, consolidation, and multiple nodules (the most common pattern is ground-glass opacity). Areas of ground-glass opacity are found both around and remote from the consolidation or nodule. The involved bronchi in lobar bronchioloalveolar carcinoma show stretching, spreading, and uniform narrowing.

References

1. Clayton F: Bronchioloalveolar carcinomas: Cell types, patterns of growth, and prognostic correlates. Cancer 57:1555-64,1986

2. Manning JT, Spjut HJ, Tschen JA: Bronchioloalveolar carcinoma: The significance of two histopathologic types. Cancer 54:525-534,1984

3. Arika M, Atagi S, Kawahara M, et al: High-resolution CT findings of diffuse bronchioloalveolar carcinoma in 38 patients. AJR 173:1623-1629, 1999

Keywords

Lung, Malignant tumor, BAC (Bronchioloalveolar Carcinoma)