Background:

Capillary malformation–arteriovenous malformation (CM-AVM) syndrome is a rare vascular disorder characterized by small cutaneous capillary malformations and an increased risk of fast flow arteriovenous malformations (AVMs). AVMs commonly involve the skin, bone, muscle, spine and brain; hepatic involvement has rarely been reported. Diagnosis is established by characteristic clinical findings and a pathogenic variant in EPHB4 or RASA1.

Case Presentation:

A 4-day-old late preterm male presented with signs of cardiac dysfunction, found to have a large high output hepatic AVM.

Clinical Course:

The patient was admitted to the NICU for management of cardiac failure. Echocardiography demonstrated suprasystemic right ventricular systolic pressures, moderate tricuspid regurgitation, right atrial dilation, and pulmonary hypertension. Ultrasonography identified a large, high-flow hepatic AVM.

Genetic testing revealed a pathogenic variant in EPHB4, confirming the diagnosis of CM-AVM syndrome. The patient underwent staged endovascular management with coil embolization on days of life 4 and 10. Post embolization angiography demonstrated marked reduction in arteriovenous shunting.

After one month, echocardiography showed normal biventricular size and systolic function with trivial tricuspid regurgitation. Follow up liver ultrasonography demonstrated no AVM within the liver.

Conclusion:

CM-AVM syndrome is associated with AVMs that may result in significant morbidity, including hemorrhage, heart failure, and neurologic complications. This case highlights an unusual presentation of CM-AVM syndrome with hepatic involvement, an organ not classically associated with this condition. Our findings underscore the importance of considering visceral AVMs in affected patients and supports the need for further research to better characterize the prevalence, clinical significance, and management of hepatic AVMs in CM-AVM syndrome.

References:

1. Bayrak-Toydemir P, Stevenson DA. Capillary Malformation-Arteriovenous Malformation Syndrome. 2011 Feb 22 [Updated 2019 Sep 12]. In: Adam MP, Bick S, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2025. Available from: https://www.ncbi.nlm.nih.gov/books/NBK52764/

2. Wooderchak-Donahue, Whitney L et al. “Phenotype of CM-AVM2 caused by variants in EPHB4: how much overlap with hereditary hemorrhagic telangiectasia (HHT)?.” Genetics in medicine : official journal of the American College of Medical Genetics vol. 21,9 (2019): 2007-2014. doi:10.1038/s41436-019-0443-z