A man in his mid-30s presented with erythrocytosis. His hemoglobin was 18.4 g/dL (reference, 13 to 17 g/dL), hematocrit, 57.3% (reference, 39% to 51%), and red blood cells 6.82 million/μL (reference, 4.1 to 5.7 million/μL). He denied tobacco exposure and pulmonary or cardiac symptoms or diseases. He has had recurrent nosebleeds since a young age. His father and son also had frequent nosebleeds but no erythrocytosis. Because of personal coronavirus disease 2019 concerns, the patient acquired a fingertip pulse oximeter that, despite the lack of respiratory symptoms, showed the oxygen saturation to be 89% to 90%.
The otolaryngologist exam revealed telangiectasias throughout the nasal cavity, including the middle turbinate (Figure A). A computed tomographic scan of the chest showed a pulmonary arteriovenous malformation (AVM) with large feeding artery (dotted arrow) and early filling pulmonary vein (solid arrow) (Figure B). Axial image (Figure C) showed the peripheral right lower lobe AVM nidus (dotted arrow), supplied by a 10-mm feeding artery and a 13-mm early filling pulmonary vein shunting directly into the left atrium (solid arrow). Magnetic resonance angiography of the brain showed no aneurysm or AVM. The patient tested negative for the JAK2 gene p.V617F mutation but showed a heterozygous (nonpathogenic) mutation of the ACVRL1 gene (C.688A>T) that is associated with hereditary hemorrhagic telangiectasia (HHT).
1The same mutation was detected in his father. The patient’s manifestations met the Curacao diagnostic criteria for HHT.
- Bossler A.D.
- Richards J.
- George C.
- Godmilow L.
- Ganguly A.
Novel mutations in ENG and ACVRL1 identified in a series of 200 individuals undergoing clinical genetic testing for hereditary hemorrhagic telangiectasia (HHT): correlation of genotype with phenotype.
Hum Mutat. 2006; 27: 667-675
2Pulmonary AVM is a rare cause of hypoxemia-induced erythrocytosis, and a potentially serious manifestation of HHT occurring in approximately 80% of patients.
- Shovlin C.L.
- Guttmacher A.E.
- Buscarini E.
- Faughnan M.E.
- Hyland R.H.
- Westermann C.J.
- Kjeldsen A.D.
- Plauchu H.
Diagnostic criteria for hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome).
Am J Med Genet. 2000; 91: 66-67
Potential Competing Interests
The authors report no competing interests.
- Novel mutations in ENG and ACVRL1 identified in a series of 200 individuals undergoing clinical genetic testing for hereditary hemorrhagic telangiectasia (HHT): correlation of genotype with phenotype.Hum Mutat. 2006; 27: 667-675
- Diagnostic criteria for hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome).Am J Med Genet. 2000; 91: 66-67
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