Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Adenoid cystic carcinoma of the left main bronchus
- Radiologic Findings
- A chest PA radiograph reveals no remarkable finding in the lungs, mediastinum and pleura. On contrast enhanced chest CT scan of axial and coronal reformation, irregular enhancing wall thickening with intraluminal protrusion is noted in distal left main bronchus. Mild air trapping is seen in left upper lobe on lung window scan.
Increased uptake is seen in the lesion of left main bronchus on FDG PET-CT scan (SUVmax 3.29). On bronchoscopy, submucosal mass with endobronchial protrusion was identified and which was associated with mucosal nodularity. Bronchoscopic biopsy specimen revealed poorly differentiated carcinoma with focal glandular growth pattern and adenoid cystic carcinoma was confirmed with immunohistochemistry.



- Brief Review
- Adenoid cystic carcinoma (ACC) is the most common type of lung cancer of salivary gland origin in the central airway. ACC has an equal sex distribution and commonly occurs in the 4th and 5th decades of life. ACC tends to occur in the central airways such as the trachea, main bronchus, or lobar bronchus and a peripheral or segmental location is uncommon. ACC has a striking tendency toward submucosal extension and manifests with circumferential and infiltrative growth. The longitudinal extent of the tumor is greater than its transaxial extent.
Chest radiographs are usually interpreted as normal findings. However, intraluminal filling defect with irregular, smooth, or lobulated contours of the airways can be identified and the extraluminal component may be visualized if it is large enough to distort the normal mediastinal contour. On CT, the tumor has a striking tendency toward submucosal extension that manifests as an intraluminal mass of soft tissue attenuation with extension through the airway wall, a diffuse or circumferential airway wall thickening, a soft tissue mass filling the airway, or a homogeneous mass encircling the airway with wall thickening. On PET-CT scan, variable FDG uptake has been reported depending on the grade of tumor differentiation. Distant metastasis occurs late in the disease course. Metastasis is very unusual and regional lymph node metastasis may be present in up to 10% of the primary tumors at the time of diagnosis.
- Please refer to
Case 115, Case 209, Case 312, Case 418, Case 804, Case 878, -
KSTR imaging conference cases 2010 Sprng Case 1
,
KSTR Imaging conference 2010 Summer Case 10,
- References
- Kwak SH, Lee KS, Chung MJ, Jeong YJ, Kim GY, Kwon OJ. Adenoid cystic carcinoma of the airways: helical CT and histopathologic correlation. AJR 2004;183:277–281
Park CM, Goo JM, Lee HJ, Kim MA, Lee CH, Kang MJ. Tumors in the tracheobronchial tree: CT and FDG PET features. RadioGraphics 2009; 29:55–71
- Keywords
- Airway, Malignant tumor,