대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Adenocarcinoma with bronchoalveolar features (diffuse involvement and cystic change)

Radiologic Findings

Fig 1. Chest simple radiograph shows diffuse ground-glass opacities accompanying cystic portions in right lung.

Figs 2-4. Initial high-resolution CT scans show diffuse ground-glass opacities in right lung. Multiple air cysts are noted in the ground-glass opacities. Subtle ground-glass opacity is seen in lingular division of left upper lobe and left lower lobe.

VATS biopsy was performed. The pathological diagnosis was adenocarcinoma with bronchioloalveolar pattern. Multiple cyscles of combination chemotherapy were performed. However, dyspnea, cough, and sputum were aggravated.

Figs 5-7. High-resolution CT scans obtained 17 months after initial CT show diffuse ground-glass opacities and consolidation accompanying multiple air cysts in both lungs. The bronchus in the involved lesion is stretched and squeezed. Compared with initial CT, the disease is markedly aggravated.

Brief Review

According to Akira et al. (1), high-resolution CT findings of diffuse bronchioloalveolar carcinoma in 38 patients were classified into three patterns: predominantly ground-glass (n=4), consolidative (n=22), and multinodular (n=12). Most patients with diffuse bronchioloalveolar carcinoma had a mixture of these findings. Cavitation of major consolidation was found in nine patients and cavitation of accessory nodules or thin-walled cystic lesions in six patients. In two patients, the onset of or increase in extent of the cystic lesions was seen within areas of ground-glass attenuation or consolidation.

Herein we present a case of adenocarcinoma mixed type with bronchioloalveolar features showing diffuse involvement and serially increasing cystic change. According to WHO classification of lung and pleural tumors proposed in 1999, the diagnosis of bronchioloalveolar carcinoma is limited to the non-invasive, localized tumors that show lepidic growth. In the cases that show stromal, vascular or pleural invasion, the pathological diagnosis should be adenocarcinoma, mixed type with bronchioloalveolar features. Therefore, most cases diagnosed as diffuse (not localized) bronchioloalveolar carcinoma before 1999 are adenocarcinoma, mixed type with bronchioloalveolar features. The CT features described by Akira et al. (1) can be applied to this case.

Cavitary lesions in bronchioloalveolar carcinoma are reported to be rare on the basis of radiographic findings (2,3). A CT study documented a 40% incidence of cavity or cyst in consolidative bronchioloalveolar carcinoma (4). CT is superior to chest radiography in detecting small cavities or cysts. Indeed, the incidence of cavitation indiffuse bronchioloalveolar carcinoma seems higher than expected. Moreover, cystic lesions may occur during the course of the disease. Cavitation or cysts can occur in association with bronchioloalveolar carcinoma in several ways. True cavitation is caused by tumor growth through ischemic necrosis, but it is unusual because the unique nondestructive growth pattern of bronchioloalveolar carcinoma usually preserve perfusion to the involved area of the lung (3). Ohba et al. (5) reported a 47-year-old woman in whom chest radiography showed bilateral, diffuse reticulonodular infiltrates with multiple cysts 3-10mm in diameter and numerous small nodules with central pinholes. At autopsy, bilateral cystic destruction of the pulmonary parenchyma was seen. The pathogenesis of cyst formation was thought to be due to two major mechanisms: central necrosis within the nodule and, more commonly, check-valve obstruction at the terminal bronchiole level. Thickened fibrous terminal bronchioles were found in some sections, which could account for the check-valve obstruction and formation of emphysematous cysts.

References

1. Akira M, Atagi S, Kawahara M, Iuchi K, Johkoh T. High-resolution CT findings of diffuse bronchioloalveolar carcinoma in 38 patients. AJR Am J Roentgenol 1999;173:1623-1629.

2. Hill CA. Bronchioloalveolar carcinoma: a review. Radiology 1984;150:15-20.

3. Miller WT, Husted J, Freiman D, Atkinson B, Pietra GG. Bronchioloalveolar carcinoma: two clinical entities with one pathologic diagnosis. AJR Am J Roentgenol 1978;130:905-912.

4. Aquino SL, Chiles C, Halford P. Distinction of consolidative bronchioloalveolar carcinoma from pneumonia: do CT criteria work. AJR Am J Roentgenol 1998;171:359-363.

5. Ohba S, Takashima T, Hamada S, Kitagawa M. Multiple cystic cavitary alveolar-cell carcinoma. Radiology 1972;104:65-66.

Keywords

Lung, Malignant tumor,