대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Multiple Arterio-Venous Malformations (AV Fistulas)

Radiologic Findings

- CT scans show three small subpleural nodules. The nodules are connected to serpiginous linear opacities, suggestive of vascular structures.

- Contrast-enhanced mediastinal setting CT scan shows strong enhancement of one of the nodules.

- These findings suggest multiple AVM nidus with a feeding artery and a draining vein.

Brief Review

1. Congenital pulmonary arteriovenous malformation (AVM, arteriovenous fistula, arteriovenous aneurysm) is considered to be caused by a defect in the terminal capillary loops that results in dilatation and the formation of thin-walled vascular sacs.

2. About 40 to 65 % of patients have AV communications elsewhere, including the skin, mucous membranes, and other organs. This condition, known as hereditary hemorrhagic telangiectasia or Rendu-Osler-Weber disease, is of simple, dominant transmission and not sex-linked.

3. Although it is assumed that the vascular defects are present at birth, they are seldom manifested clinically until adult life when the vessels have been subjected to pressure over several decades.

4. Grossly, pulmonary AVMs appear as spherical, vascular masses ranging in diameter from 1 mm to several centimeters just beneath the pleura or adjacent to bronchovascular bundles.

5. AVM are supplied and drained by several vessels, the draining veins usually being somewhat larger than the feeding arteries.

6. Radiologic Findings of AVM

- most common in the lower lobes.
- single in two thirds, and multiple in a third of cases.
- round or oval, somewhat lobulated in contour, but sharply defined.
- calcification in some cases (phleboliths).
- on CT scan, feeding arteries and draining veins are easily identified.

7. Clinical Manifestations

- Occurs twice as frequently in women as in men and usually are not recognized until the third or fourth decade of life.
- May be asymptomatic but often complain of hemoptysis or dyspnea.
- Signs include cyanosis, finger clubbing, and contunuous murmur or bruit audible over the lesion.
- Because of strong association with hereditary telangiectasia, extrathoracic manifestations of disease also are fairly common. (epistaxis, telengiectasis in the skin or mucous membranes,, gastrointestinal tract hemorrhage)
- CNS complications (intracerebral aneurysmal rupture, metastatic abscess, hypoxemia, cerebral embolism, cerebral thrombosis from secondary polycythemia)
- Prognosis is good (embolotherapy, surgical resection)

References

Fraser RS, Pare JAP, Fraser RG, Pare PD. Synopsis of diseases of the chest. 2nd ed. Philadelphia; W. B. Saunders. 1994:277-279

Keywords

Lung, Vascular, Congenital,