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Hereditary Hemorrhagic Telangiectasia

By Drs K. Rauhilla, Mamta Verma, and Sonia Arunabh

Volume 56 - Issue 3 - March 2016

A 42-year-old woman with no known relevant past medical history presented with a sudden onset of slurred speech and right-arm weakness. She had no history of hypertension, hyperlipidemia, neurologic disorders, headaches, vision changes, or use of oral contraceptives.

She reported the onset of nosebleeds at age 16, with progressively severe bleeds over the past 5 years. She denied easy bruising and excessive bleeding after trauma or dental procedures, and she denied a history of chronic sinusitis, melena, or rectal bleeding. Her family history is significant for a father with frequent nosebleeds.

Physical examination. Physical examination findings were notable for conjunctival pallor and multiple telangiectasias of the nasal ala, inferior nasal turbinate, lips, buccal mucosa, and tongue. Neurologic examination revealed word-finding difficulties and decreased strength (4/5) in the proximal and distal right upper extremity.

Diagnostic tests. Magnetic resonance imaging (MRI) of the brain showed an acute left frontoparietal infarct. Computed tomography angiography of the chest revealed multiple pulmonary arteriovenous malformations (AVMs). Lower-extremity venous duplex ultrasonography results were positive for a deep vein thrombosis, and the patient’s cerebral vascular accident was attributed to paradoxical emboli by means of pulmonary AVMs.

A diagnosis of hereditary hemorrhagic telangiectasia (HHT) was established based on clinical symptoms. She underwent successful transcatheter embolization of 3 pulmonary AVMs.

Discussion. HHT is a rare autosomal dominant disease of aberrant blood vessel formation leading to AVMs. It involves multiple organ systems, including the skin, mucosal membranes, lungs, gastrointestinal tract, liver, and brain. The incidence of HHT in North America is approximately 1 in 10,000.1

Among the most common clinical features of the disease are epistaxis and mucocutaneous telangiectasias. AVMs also can develop in lungs, liver, gastrointestinal tract, and brain, leading to potentially catastrophic complications. Pulmonary AVMs affect from 15% to 30% of patients with HHT and can lead to hypoxemia, high-output heart failure, stroke, and brain abscess. Approximately 70% of pulmonary AVMs occur in patients with HHT.2

Contrast echocardiography is the initial screening test for the presence of pulmonary AVMs. When contrast echocardiography findings are positive, computed tomography of the chest is warranted to evaluate the necessity of treatment.3

Pulmonary AVMs of at least 3 mm in diameter require treatment with transcatheter embolization.2 An international expert panel4 has recommended that clinicians screen all patients with HHT with contrast echocardiography every 5 to 10 years for the early detection of pulmonary AVMs. The panel also advises adults with HHT to receive MRI of the brain to screen for cerebrovascular AVMs to detect occult lesions.4

HHT frequently goes unrecognized by clinicians. Diagnostic criteria for the disease include the presence of epistaxis, a family history of HHT, multiple telangiectasias at characteristic sites, and visceral lesions. The diagnosis is definitive when at least 3 of these 4 criteria are met. HHT is possible and should be suspected in the presence of 2 or more criteria, but its presence is unlikely if fewer than 2 criteria are met.5

This case highlights the importance of early diagnosis of HHT and appropriate screening of patients for the condition. Awareness of the clinical presentation and complications of HHT can reduce or prevent related morbidity and mortality.

References:

  1. McDonald J, Bayrak-Toydemir P, Pyeritz RE. Hereditary hemorrhagic telangiectasia: an overview of diagnosis, management, and pathogenesis. Genet Med. 2011;13(7):607-616.
  2. Olitsky SE. Hereditary hemorrhagic telangiectasia: diagnosis and management. Am Fam Physician. 2010;82(7):785-790
  3. Meek ME, Meek JC, Beheshti MV. Management of pulmonary arteriovenous malformations. Sem Intervent Radiol. 2011;28(1):24-31.
  4. Faughnan ME, Palda VA, Garcia-Tsao G, et al. International guidelines for the diagnosis and management of hereditary haemorrhagic telangiectasia. J Med Genet. 2011;48(2):73-87.
  5. Shovlin CL, Guttmacher AE, Buscarini E, et al. Diagnostic criteria for hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome). Am J Med Genet. 2000;91(1):66-67.