Pulmonary arteriovenous malformation

Case contribution: Dr Radhiana Hassan


  • A 55- year- old man
  • He had underlying diabetes mellitus ,  hypertension and valvular heart disease.
  • Presented with shortness of breath and cough.
  • There was no associated chest pain or fever.
  • Clinically this patient had congestive cardiac failure, NYHA Class II.

Chest radiograph findings:

  • There are well-defined nodular opacities in the right lower zone below the right hemidiaphragm (yellow arrows)
  • Patient also had gross cardiomegaly
  • No feature of congestive cardiac failure. No pleural effusion.

CT scan findings:

  • Axial CECT image , lung window setting (A) shows multiple nodular lesions within the right lower lobe (block arrow)
  • It shows similar density with vessels on post contrast images
  • MIP image (B) shows the nodular densities were arteriovenous malformation with a single supplying artery and draining vein.

Diagnosis: Pulmonary arteriovenous malformation.


  • Pulmonary arteriovenous malformation is not a common clinical problem.
  • The estimated incidence is thought to be around 2-3 per 100,000 population.
  • Mostly are asymptomatic, however patient can present with dyspnoea due to right-to-left shunting.
  • It is often unilateral. Although can potentially affect any part of the lung, there is a recognised predilection towards the lower lobes (50-70%).
  • Radiologically, this condition is an important differential diagnosis of pulmonary nodules detected on chest radiograph.
  • CT is often the diagnostic imaging modality of choice. The characteristic presentation of a PAVM on non-contrast CT is a homogeneous, well-circumscribed, non-calcified nodule up to several centimetres in diameter or the presence of a serpiginous mass connected with blood vessels. Post contrast image demonstrates enhancement of the feeding artery, the aneurysmal part, and the draining vein on early-phase sequences.
  • They can be classified as simple, complex or diffuse.
    • simple type: commonest; has a single segmental artery feeding the malformation; the feeding segmental artery may have multiple subsegmental branches that feed the malformation but must have only one single segmental level
    • complex type: have multiple segmental feeding arteries (~20%)
    • diffuse type: rare (~5% of lesions); the diffuse form of the disease is characterised by hundreds of malformations; some patients can have a combination of simple and complex AVMs within a diffuse lesion


Elfeky M et al, Pulmonary arteriovenous malformation at https://radiopaedia.org/articles/pulmonary-arteriovenous-malformation

Author: radhianahassan