Faculty Bibliography

Capillary malformation-arteriovenous malformation (CM-AVM) is an autosomal-dominant disorder, caused by heterozygous RASA1 mutations, and manifesting multifocal CMs and high risk for fast-flow lesions. A limited number of patients have been reported, raising the question of the phenotypic borders. We identified new patients with a clinical diagnosis of CM-AVM, and patients with overlapping phenotypes. RASA1 was screened in 261 index patients with: CM-AVM (n = 100), common CM(s) (port-wine stain; n = 100), Sturge-Weber syndrome (n = 37), or isolated AVM(s) (n = 24). Fifty-eight distinct RASA1 mutations (43 novel) were identified in 68 index patients with CM-AVM and none in patients with other phenotypes. A novel clinical feature was identified: cutaneous zones of numerous small white pale halos with a central red spot. An additional question addressed in this study was the "second-hit" hypothesis as a pathophysiological mechanism for CM-AVM. One tissue from a patient with a germline RASA1 mutation was available. The analysis of the tissue showed loss of the wild-type RASA1 allele. In conclusion, mutations in RASA1 underscore the specific CM-AVM phenotype and the clinical diagnosis is based on identifying the characteristic CMs. The high incidence of fast-flow lesions warrants careful clinical and radiologic examination, and regular follow-up.

PHACE syndrome represents the association of large infantile hemangiomas of the head and neck with brain, cerebrovascular, cardiac, ocular, and ventral or midline defects. Cardiac and cerebrovascular anomalies are the most common extracutaneous features of PHACE, and they also constitute the greatest source of potential morbidity. Congenital heart disease in PHACE is incompletely described, and this study was conducted to better characterize its features. This study of the International PHACE Syndrome Registry represents the largest central review of clinical, radiologic, and histopathologic data for cardiovascular anomalies in patients with PHACE to date. Sixty-two (41%) of 150 subjects had intracardiac, aortic arch, or brachiocephalic vessel anomalies. Aberrant origin of a subclavian artery was the most common cardiovascular anomaly (present in 31 (21%) of 150 subjects). Coarctation was the second most common anomaly, identified in 28 (19%) of 150 subjects, and can be missed clinically in patients with PHACE because of the frequent association of arch obstruction with aberrant subclavian origin. Twenty-three (37%) of 62 subjects with cardiovascular anomalies required procedural intervention. A greater percentage of hemangiomas were located on the left side of the head and neck in patients with coarctation (46% vs 39%); however, hemangioma distribution did not predict the presence of cardiovascular anomalies overall. In conclusion, PHACE is associated with a high risk of congenital heart disease. Cardiac and aortic arch imaging with detailed assessment of arch patency and brachiocephalic origins is essential for any patient suspected of having PHACE. Longitudinal investigation is needed to determine the long-term outcomes of cardiovascular anomalies in PHACE.

BACKGROUND: Infantile hemangioma (IH) clearance may be slow or incomplete in response to pulsed dye laser (PDL) or propranolol alone. OBJECTIVES: To evaluate whether IH treated with PDL and propranolol displayed more rapid and complete clearance than IH treated with propranolol alone. MATERIALS AND METHODS: Retrospective review of facial-segmental IH treated with propranolol and PDL and controls treated with propranolol was conducted. Blinded physicians used patient photographs to select clearance level and the earliest date of near-complete clearance. Days of propranolol, PDL sessions, and propranolol dose, each until date of near-complete clearance; total days of propranolol; and total propranolol dose were recorded. RESULTS: Infantile hemangiomas treated concurrently with propranolol and PDL achieved complete clearance (6/12) more often than IH treated with propranolol followed by PDL (2/5) or IH treated with propranolol alone (1/8; difference in clearance scores p = .01) and achieved near-complete clearance after fewer days of propranolol (mean 92 days for concurrent propranolol and PDL vs 288 days for propranolol; p < .001). Cumulative propranolol dose until near-complete clearance was lowest in the concurrent propranolol and PDL group (149.16 vs 401.25 mg/kg for propranolol; p < .001). CONCLUSION: Facial-segmental IH treated with propranolol and PDL displayed morerapid and complete clearance and required a lower cumulative propranolol dose to achieve near-complete clearance.

PHACE syndrome (OMIM #606519) is a neurocutaneous syndrome of unknown etiology and pathogenesis. We report on an individual with PHACE syndrome with a complete deletion of SLC35B4 on 7q33. In order to further analyze this region, SLC35B4 was sequenced for 33 individuals with PHACE syndrome and one parental set. Common polymorphisms with a possible haplotype but no disease causing mutation were identified. Sixteen of 33 samples of the PHACE syndrome patients were also analyzed for copy number variations using high-resolution oligo-comparative genomic hybridization (CGH) microarray. A second individual in this cohort had a 26.5 kb deletion approximately 80 kb upstream of SLC35B4 with partial deletion of the AKR1B1 on 7q33. The deletions observed on 7q33 are not likely the singular cause of PHACE syndrome; however, it is possible that this region provides a genetic susceptibility to phenotypic expression with other confounding genetic or environmental factors.

Propranolol is a non-selective beta-adrenergic antagonist successfully used in a case of kaposiform hemangioendothelioma (KHE) associated with Kasabach-Merritt phenomenon (KMP). We report 11 patients treated with propranolol for KHE and the related variant tufted angioma (TA), six of whom also had KMP. The varied responses to treatment, with only 36% responding in our series, demonstrate the need for further study of this medication before routine use for these indications.

The term "vascular anomalies" embraces a spectrum of medical conditions characterized by abnormal growth or development of blood and/or lymphatic vessels. Patient management is frequently provided in a multidisciplinary team approach, as there are many facets to evaluation and treatment. Clinical and basic research during the past decade has enhanced our knowledge, providing insight into possible etiologies, associated genetic mutations, cellular mechanisms modulating the development, and natural history of these disorders. Concomitantly, new therapeutic agents have been identified, which has transformed patient management. In this review, a brief overview of the field including an update in basic research is presented, followed by a discussion of current therapies and their purported mechanism of action.