대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Endobronchial metastasis of renal cell carcinoma

Radiologic Findings

Chest PA and lateral view shows atelectasis of the left upper lobe. CT images shows well enhancing endobronchial mass in left upper lobe with distal mucus impaction, and several enlarged lymph nodes in subaortic and left peribronchial area. On FDG PET CT, the mass and lymph nodes show hypermetabolism (SUV max 5.3). Bronchoscopic image shows hypervascular polypoid mass in the left upper lobe bronchus. The patient had a history of right nephrectomy due to renal cell carcinoma.

Brief Review

The common sources of endobronchial metastases are kidney, breast, and colorectal cancers.
The symptoms associated with the endobronchial metastasis regardless of the primary sites are similar to those associated with a primary bronchogenic carcinoma or other primary endobronchial tumors. Therefore, it may be impossible to differentiate an endobronchial metastasis from these carcinomas on the basis of the symptoms.
There are several points on CT images that may assist in distinguishing an endobronchial tumor from a primary bronchogenic carcinoma. In endobronchial tumors, the long axis of the tumor is parallel to that of the bronchus, and may show a branching pattern adapting airways branches.
Strong enhancement is a characteristic CT finding of a renal cell cancer (RCC). Some studies have found that very strong enhancement of the mass is a unique CT finding of a conventional renal carcinoma, which can be used to differentiate this subtype from the other RCC subtypes. One study reported that the specificity for differentiating a conventional renal carcinoma from the other subtypes was 100% with 84 HU as the cutoff value in the corticomedullary phase CT.

References

1. Park, C.M., et al., Endobronchial metastasis from renal cell carcinoma: CT findings in four patients. Eur J Radiol 2004;51(2): 155-9
2. Seo, J.B., et al., Atypical pulmonary metastases: spectrum of radiologic findings. Radiographics 2001; 21(2):403-17
3. Chang, J.M., et al., False Positive and False Negative FDG-PET Scans in Various Thoracic Diseases. Korean J Radiol, 2006;7(1):57-69
4. Jeong, Y.J., et al., Solitary Pulmonary Nodule: Characterization with Combined Wash-in and Washout Features at Dynamic Multidetector CT. Radiology 2005;237:675-683
5. Park, J.W., M.K. Jo, and H.M. Lee, Significance of 18F-fluorodeoxyglucose positron-emission tomography/computed tomography for the postoperative surveillance of advanced renal cell carcinoma. BJU Int;2009;103(5):615-9
6. Dursun, A.B., et al., Endobronchial metastases: a clinicopathological analysis. Respirology 2005;10(4):510-514

Keywords

airway, malignant tumor, metastasis,