Beyond Hereditary Haemorrhagic Telangiectasia (HHT): Capillary Malformation-Arteriovenous Syndrome (CM-AVM).
I Haydar, P Leahy, T M O'Connor
✦ AI-curated · Sources linked
Case in brief
An asymptomatic woman in her forties was referred for suspected hereditary haemorrhagic telangiectasia (HHT) after mucocutaneous telangiectasia was noted on her face, lips and hands. Examination also found an audible bruit over the left posterior chest wall. Brain and spine MRI showed no cerebral arteriovenous malformations. Genetic testing identified a heterozygous EPHB4 splice variant consistent with capillary malformation–arteriovenous malformation (CM-AVM) syndrome and found no HHT-associated mutations. She received counselling about warning signs of haemorrhage, genetic counselling and routine follow-up through an HHT clinic.
What made this case unusual
The HHT-like mucocutaneous lesions were associated with an EPHB4 variant indicating CM-AVM, a genetically distinct syndrome; the chest-wall bruit was another notable finding.
Diagnostic / clinical pearl
When mucocutaneous vascular lesions suggest HHT, consider CM-AVM as a clinical mimic; genetic testing can distinguish the syndromes and inform surveillance and counselling.