Vascular Anomalies: Evolving Understanding
Ilona Frieden, MD, University of California, San Francisco, presented the "Founders' Lecture," entitled "Lessons Learned From Vascular Anomalies," at the 28th Annual Meeting of the Society for Pediatric Dermatology (SPD). Dr. Frieden discussed the evolution in the understanding of the pathogenesis, clinical presentation, diagnosis, and management of vascular lesions, including hemangiomas and malformations.
Mulliken and Glowacki originally proposed a classification of vascular birthmarks that divided lesions into hemangiomas and malformations. A revised nosology, initially proposed at the International Society for the Study of Vascular Anomalies (ISSVA) in 1996, divides vascular anomalies of infants and children into 2 broad types: tumors and malformations. Dr. Frieden stated that tumors are further subdivided into 2 groups. One group includes hemangiomas of infancy, pyogenic granulomas, and 2 types of congenital hemangiomas: non-involuting congenital hemangiomas (known as NICH) and rapidly involuting congenital hemangiomas (known as RICH). A second tumor group includes tufted angiomas, kaposiform hemangioendotheliomas, and spindle-cell hemangioendotheliomas. Malformations are divided into low-flow lesions (including port-wine stains, venous malformations, lymphatic malformations, and some combined lesions) and high-flow lesions (including arteriovenous malformations and Parkes-Weber syndrome).
A diagnosis of hemangioma means different things to different people, stated Dr. Frieden. In a recently published study, current editions of genetics textbooks were reviewed for the accuracy of their terminology describing vascular lesions. Agreement with the ISSVA classification ranged from only 22% to 75%. "Hemangioma" was the most commonly used term but had only a 23% rate of agreement with the ISSVA classification.
Dr. Frieden discussed the utility of the immunohistological marker Glut-1, an erythrocyte-type glucose transport protein found to be a marker of hemangiomas of infancy in all stages of development, proliferation, plateau, or involution. In contrast, non-involuting and rapidly involuting congenital hemangiomas are distinct in clinical appearance and in their natural history, and are negative for Glut-1 staining.
Hemangiomas have marked clinical heterogeneity. Dr. Frieden stressed that this heterogeneity has direct clinical consequences as physicians try to separate "ditzel" lesions -- small insignificant hemangiomas -- from those associated with functional significance, syndromic anomalies, or other "disasters."
There are several recent studies looking at the characterization of hemangiomas based on morphology and location. Hemangiomas are assigned to localized, segmental, multifocal, or indeterminate categories. Segmental hemangiomas appear to be more likely to be associated with other anomalies, complications such as ulceration, poorer outcome, and the need for treatment.
Vascular malformations should be thought of based on physiology and anatomy, said Dr. Frieden, rather than the traditional syndromic name. For instance, Klippel-Trenaunay syndrome is a triad of capillary vascular malformation (port-wine stain), venous varicosities, and soft-tissue and/or bony hypertrophy. In a poster at the SPD, Dr. Catherine Maari of Children's Hospital, San Diego, and the University of California, San Diego, and Dr. Frieden presented a retrospective study of Klippel-Trenaunay Syndrome, proposing that a clinical presentation of "geographic," well-defined stains was more highly associated with lymphatic malformation and complications than was a clinical presentation of "blotchy" stains.
Dr. Frieden also suggested that another condition, cutis marmorata telangiectatica congenital (CMTC), be carefully considered from a fresh perspective. CMTC does not fit easily into the new vascular malformation nosology, and may be a label that is applied to several different entities, including port-wine stains, reticulated capillary malformations, and livedo-like lesions.
Dr. Frieden concluded by discussing the utility and limitations of laser therapy for vascular lesions and the need for a multidisciplinary approach to complex vascular anomalies. She also emphasized the need for physicians and healthcare workers involved in the care of patients with these anomalies to keep an open mind and appreciate their different clinical presentations, and to keep up to date on advances in understanding, changes in terminology, and new approaches to therapy.
Medscape Dermatology. 2002;3(2) © 2002 Medscape
Cite this: Two Colleagues, Two Perspectives: Report From the Society for Pediatric Dermatology Annual Meeting, Part 2 - Medscape - Oct 01, 2002.