<aside>

Hereditary Hemorrhagic Telangiectasia (HHT), also known as Osler–Weber–Rendu syndrome, is an autosomal dominant vascular disorder characterized by mucocutaneous telangiectasias and visceral arteriovenous malformations (AVMs) due to abnormal vessel formation and loss of capillary beds.

</aside>

https://www.youtube.com/watch?v=Lsq_GgWu5r4

https://www.youtube.com/watch?v=z2gALD8xSNE

![Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease that manifests as vascular malformations in the brain, lung, liver, gastrointestinal tract, nasal mucosa, and skin. Diagnosis and management of HHT is guided in large part by imaging studies, making it a condition with which the radiology community needs familiarity. Proper screening and care lead to improved morbidity and mortality in patients with HHT.

Hetts SW, Shieh JT, Ohliger MA, Conrad MB. Hereditary Hemorrhagic Telangiectasia: The Convergence of Genotype, Phenotype, and Imaging in Modern Diagnosis and Management of a Multisystem Disease. Radiology. 2021;300(1):17-30. doi:https://doi.org/10.1148/radiol.2021203487](attachment:d1b83bb2-e8c4-4e0d-bf28-a919ce189e29:images_large_radiol.2021203487.va.jpeg)

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease that manifests as vascular malformations in the brain, lung, liver, gastrointestinal tract, nasal mucosa, and skin. Diagnosis and management of HHT is guided in large part by imaging studies, making it a condition with which the radiology community needs familiarity. Proper screening and care lead to improved morbidity and mortality in patients with HHT.

Epidemiology

Prevalence: ~1 in 5,000–10,000
Inherited in autosomal dominant pattern
High penetrance, but variable expressivity
Onset: usually 2nd–4th decades of life

Pathophysiology

Gene Mutations	Subtype / Syndrome
ENG (endoglin)	HHT type 1 – associated with pulmonary and cerebral AVMs
ACVRL1 (ALK1)	HHT type 2 – associated with hepatic AVMs
SMAD4	Combined HHT + juvenile polyposis syndrome

Affects TGF-β signaling pathway, leading to fragile, dilated blood vessels without intervening capillary beds.

Clinical features

<aside>

HHT primarily results in two types of vascular anomaly — large arteriovenous malformations (AVMs) affecting internal organs and small telangiectases (that is, abnormal small blood vessels), which can be found internally and in typical and visible sites such as the lips, tongue and finger pads.

</aside>

System	Findings
ENT	Recurrent epistaxis (90–95%) – often starting in childhood
Skin	Telangiectasias on lips, tongue, face, fingertips
Pulmonary	Pulmonary AVMs (PAVMs): dyspnea, hypoxemia, paradoxical emboli
Cerebral	Cerebral AVMs or aneurysms – risk of hemorrhagic stroke or seizure
Hepatic	Hepatic AVMs: high-output cardiac failure, portal hypertension, biliary ischemia
Gastrointestinal	GI bleeding from AVMs – especially in stomach and duodenum, chronic anemia
Spinal	Spinal AVMs – rare, risk of hemorrhage or myelopathy

![Clinical manifestations in patients with HHT (A, B) were collected from a 62-year-old woman with HHT. Multiple maroon-colored telangiectases (arrows) were seen on her lips, tongue, face (A), and fingers (B). Enteroscopy shows scattered telangiectases (C) CT pulmonary angiogram shows an AVM in the lower lobe of the right lung, associated with the right inferior pulmonary vein (D). CTs with contrast of another 35-year-old woman with HHT who had hepatic AVMs showed that the hepatic vein, portal vein, and their branches enhanced earlier during the arterial phase, indicating the existence of hepatic arteriovenous shunt (E) and arterioportal shunt (F). AVM = arteriovenous malformation, CT = computed tomography, HHT = hereditary hemorrhagic telangiectasia.

Li, Sen MD; Wang, Shu-Jie MD; Zhao, Yong-Qiang MD. Clinical features and treatment of hereditary hemorrhagic telangiectasia. Medicine 97(31):p e11687, August 2018. | DOI: 10.1097/MD.0000000000011687](attachment:a9208811-4c54-4555-a1d5-210034100e89:Original.00005792-201808030-00075.F1-75.jpeg)

Clinical manifestations in patients with HHT (A, B) were collected from a 62-year-old woman with HHT. Multiple maroon-colored telangiectases (arrows) were seen on her lips, tongue, face (A), and fingers (B). Enteroscopy shows scattered telangiectases (C) CT pulmonary angiogram shows an AVM in the lower lobe of the right lung, associated with the right inferior pulmonary vein (D). CTs with contrast of another 35-year-old woman with HHT who had hepatic AVMs showed that the hepatic vein, portal vein, and their branches enhanced earlier during the arterial phase, indicating the existence of hepatic arteriovenous shunt (E) and arterioportal shunt (F). AVM = arteriovenous malformation, CT = computed tomography, HHT = hereditary hemorrhagic telangiectasia.

Li, Sen MD; Wang, Shu-Jie MD; Zhao, Yong-Qiang MD. Clinical features and treatment of hereditary hemorrhagic telangiectasia. Medicine 97(31):p e11687, August 2018. | DOI: 10.1097/MD.0000000000011687

Curaçao clinical criteria: