Hereditary Hemorrhagic Telangiectasia (HHT, Rendu–Osler–Weber Syndrome)

A rare autosomal dominant disorder characterized by vascular malformations affecting the skin, nasal mucosa, other mucous membranes, and internal organs.

Clinical manifestations:

Recurrent epistaxis

Telangiectasias on the skin and mucous membranes

Arteriovenous malformations (AVMs) in the lungs, liver, brain, or gastrointestinal tract may cause serious complications

Statistics: Approximately 15,000 –  10,000 ~ 1.5 million people worldwide; frequently underdiagnosed.

Diagnosis (Curacao criteria):

Recurrent epistaxis

Typical telangiectasias

Internal organ AVMs

Family history

≥3 criteria → definite diagnosis

2 criteria → possible diagnosis

Laboratory and imaging studies:

Endoscopy (for gastrointestinal telangiectasias)

CT/MRI angiography (for pulmonary or cerebral AVMs)

Genetic testing (ENG, ACVRL1, SMAD4 mutations)

Management:

Epistaxis: topical therapy, laser/radiofrequency ablation, and sometimes bevacizumab

Gastrointestinal bleeding: endoscopic coagulation, iron supplementation, transfusions in severe cases

Arteriovenous Malformations (AVMs):

Pulmonary — embolization

Cerebral — neurosurgical intervention

Hepatic — surveillance, rarely transplantation

Systemic therapy: bevacizumab, occasionally tranexamic acid․