Also known as Osler-Weber-Rendu syndrome, hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant condition characterised by (as the name suggests) multiple telangiectasia over the skin and mucous membranes. Twenty percent of cases occur spontaneously without prior family history.
There are 4 main diagnostic criteria. If the patient has 2 then they are said to have a possible diagnosis of HHT. If they meet 3 or more of the criteria they are said to have a definite diagnosis of HHT:
Multiple pinpoint red macules and papules on the tongue and perioral region, consistent with telangiectasia. These lesions are non-blanching, vascular malformations that arise from dilated postcapillary venules, a hallmark of hereditary haemorrhagic telangiectasia (Osler-Weber-Rendu syndrome).
The chest x-ray shows multiple pulmonary nodules representing arteriovenous malformations, the largest in the right mid-zone. The CT scan shows multiple hepatic arteriovenous malformations
This coronal brain section shows extensive cystic and serpiginous spaces in the right hemisphere, consistent with a large cerebral arteriovenous malformation (AVM). The lesion reflects abnormal connections between arteries and veins, bypassing the capillary network. In hereditary haemorrhagic telangiectasia (HHT), cerebral AVMs are a recognised complication and may present with seizures, focal neurological deficits, or intracerebral haemorrhage. AVMs can also remain asymptomatic and are often identified through screening in individuals with known HHT. MRI/MRA is recommended in all confirmed cases to detect cerebral AVMs early and guide management.
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