대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Rasmussen Aneurysm within Cavitary Tuberculous Lesion

Radiologic Findings

HRCT shows a large, thin-walled cavitary lesion with an air-fluid level in right mid-lung zone, suggestive of loculated hydropneumothorax in the major fissure. Note also a subpleural nodular lesion with air-meniscus sign and brochiectasis in the left lung. Unenhanced CT scan shows peripheral calcification in the subpleural nodule and small amount of left pleural effusion. Contrast-enhanced CT scan shows strong vascular enhancement of the nodular lesion.

Brief Review

Rasmussen's aneurysm is a rare phenomenon caused by weakening of the pulmonary artery wall from adjacent cavitary tuberculosis. A review of autopsy findings in patients with a history of chronic cavitary tuberculosis showed a 5% prevalence of Rasmussen's aneurysm. A destructive lung process, irrespective of its pathogenesis, can destroy adjacent lung, weaken the arterial wall, or erode any vessel in its vicinity. Progressive weakening of the arterial wall occurs as granulation tissue replaces both the adventitia and the media. The granulation tissue in the vessel wall is then gradually replaced by fibrin, resulting in thinning of the arterial wall, pseudoaneurysm formation, and subsequent rupture. Rasmussen's aneurysm involves the small to medium pulmonary artery branches that develops in the vicinity of a tuberculous cavity and usually distributed peripherally and beyond the branches of main pulmonary arteries. Hemoptysis is the usual presenting symptom and may be life-threatening when it is massive. There is the potential risk of aneurysmal rupture during diagnostic catheter angiography. Coil embolization is a safe and effective means of treating these pseudoaneurysms. (Reviewed by Eun-Ah Kim, Clinical Fellow, Samsung Medical Center)

References

1. Kim HY, Song KS, Goo JM, Lee JS, Lee KS, Lim TH. Thoracic sequelae and complications of tuberculosis. RadioGraphics 2001; 21: 839-858.
2. Patankar T, Prasad S, Deshmukh H, Mukherji SK. Fatal hemoptysis caused by ruptured giant Rasmussen's aneurysm. AJR 2000;174:262-263.
3. ED Santelli, Katz DS, Goldschmidt AM, Thomas HA. Embolization of multiple Rasmussen aneurysms as a treatment of hemoptysis. Radiology 1994; 193: 396-398.

Keywords

Vascular, Lung, Vascular, infection,