Faculty Bibliography

Kasabach-Merritt phenomenon is a serious coagulopathy associated with kaposiform hemangioendothelioma (KHE), tufted angioma, and possibly other vascular neoplasms. KHE presenting in the absence of Kasabach-Merritt phenomenon is rare, although tufted angioma frequently occurs without thrombocytopenia. We retrospectively reviewed 10 cases of KHE without Kasabach-Merritt phenomenon. The tumors appeared as soft tissue masses with the overlying skin being either normal, erythematous, or violaceous. There were no radiologic or microscopic differences in noncoagulopathic KHE as compared with coagulopathic KHE. Evidence of platelet trapping and hemosiderin deposition was seen histologically, despite normal serum platelet levels. All KHE were less than 8 cm in diameter, suggesting that tumors that grow no larger than this size are less likely to trap platelets in sufficient quantity to cause thrombocytopenia. Our series confirms that KHE appears with a wide spectrum of behavior and response to treatment. The decision as to whether or not to treat a noncoagulopathic KHE should be based on the size and location of the tumor and the possible side effects of therapy

Recent findings regarding pathways of stem/progenitor cell involvement in adult blood vessel growth (postnatal vasculogenesis) suggest new theories for the pathogenesis of vascular anomalies. The somatic growth of vascular malformations and the mysterious pattern of proliferation and involution in infantile hemangioma can no longer be purely understood through the paradigm of angiogenesis. Molecular signals for postnatal vasculogenesis are being discovered in numerous animal models of cancer and ischemia, yet little research has addressed the importance of vasculogenesis in the growth of vascular anomalies. In this review, we discuss early studies that have investigated stem/progenitor cell involvement in the pathophysiology of infantile hemangioma and other congenital vascular anomalies

BACKGROUND: Klippel-Trenaunay syndrome is a rare congenital disease characterized by extensive cutaneous vascular malformations, venous varicosities, focal abnormalities of the deep venous system, and underlying soft tissue or bony hypertrophy. Given the rarity of the disease, there is little information available to counsel patients with Klippel-Trenaunay syndrome regarding obstetric outcome. CASES: We report our experience with 3 patients in whom Klippel-Trenaunay syndrome complicated 4 pregnancies. Successful delivery of a healthy infant at or beyond 36 weeks of gestation was achieved in all pregnancies. One of the 4 pregnancies was complicated by pulmonary embolism. CONCLUSION: Klippel-Trenaunay syndrome was once thought to be a contraindication to pregnancy. With careful management, successful pregnancies can be achieved

Hemangiomas are the most common benign tumor of infancy. Most hemangiomas remain asymptomatic and can be managed by close observation; however, immediate treatment is indicated for hemangiomas that may cause significant complications. Periocular hemangiomas warrant close evaluation and early, active treatment of those with the potential to threaten or permanently compromise vision. Herein we review the clinical features of periocular hemangiomas, differential diagnosis, possible ophthalmologic complications and sequelae, and therapeutic modalities

Vascular malformations can usually be diagnosed on clinical grounds. They have a well-defined appearance on magnetic resonance imaging, which can effectively determine their tissue and flow characteristics. However, the role of cross-sectional imaging in the management of vascular malformations is not well defined. Most reviews suggest that magnetic resonance imaging should be reserved for cases in which the extent of the lesion cannot be estimated on physical examination. However, to date no group has compared the accuracy of physical examination alone to that of magnetic resonance imaging in determining this extent. A review was performed of all the patients evaluated for vascular malformations at the New York University Trunk and Extremity Vascular Anomalies Conference between July of 1994 and August of 1999. Patients who underwent magnetic resonance evaluation at other institutions and whose images were not available for review were excluded. All study patients either underwent magnetic resonance imaging examination at New York University Medical Center or had outside films reviewed at the center. The physical examination findings were compared with the magnetic resonance findings and the surgeon and radiologist made a joint decision about whether there was a correlation between the magnetic resonance and physical examination findings. Fifty-eight patients met the study criteria, 44 (76 percent) of whom were found to have more extensive disease on magnetic resonance examination than appreciated on physical examination. Of the 51 patients with low-flow vascular malformations (venous vascular malformations, lymphatic malformations, and capillary malformations), 39 (76 percent) had more extensive disease on magnetic resonance examination than on physical examination. Of the seven patients with high-flow arteriovenous malformations, five had more extensive disease on magnetic resonance. In all of the 44 patients whose magnetic resonance imaging findings did not correlate with those of the physical examination, therapeutic decision making was affected. Contrary to the conventional wisdom of published reviews, physical examination findings significantly underestimated the extent of vascular malformations in the majority of cases. Magnetic resonance imaging should be performed in all patients with vascular malformations of the trunk and extremities before therapy is planned. In an age when physicians are asked to justify their decisions, especially where the use of expensive diagnostic modalities is concerned, the situations in which these tests are indispensable must be clearly defined or else patients will be denied access to them

Vascular anomalies arise from genetic, environmental, mechanical, and/or hormonal factors. Some are inherited in a Mendelian fashion whereas others result from abnormal chromosomal segregation during gametogenesis or appear sporadically during various stages of life. Understanding the molecular basis of vascular development and vascular anomalies provides potential tools for diagnosis and treatment of the diseases

Optimal care for a subgroup of infants with complicated vascular anomalies requires prenatal diagnosis. Fetal vascular lesions are either vascular tumors or vascular malformations, both of which are often detected on routine ultrasound. Imaging, such as ultrasound and fetal MRI, can be used to examine lesions and provide the data for a differential diagnosis, which may impact the course of care both in utero and postnatally. Prenatal diagnosis provides the opportunity for antenatal intervention, parental counseling, and planning of the mode and location of delivery to optimize postnatal care. Prenatal diagnosis of vascular lesions also serves to alert the physician to the potential for associated syndromes and complications. Any indication of a vascular anomaly should be referred for further examination by an experienced multidisciplinary team of physicians to ensure the window in which evaluation, planning, and treatment can take place is not missed

Although the majority of hemangiomas of infancy undergo an uncomplicated, predictable course of proliferation followed by involution, a subset of patients sustain a more fastidious course. These include hemangiomas that, at least during part of their life cycle, have a high flow (arterial) component. Hemangiomas with high flow are most frequently located in the liver. These lesions can lead to significant morbidity, with high output cardiac failure. We have identified nonhepatic hemangiomas that have an apparent propensity to develop a high flow element--the parotid, upper arm, scalp, and rarely the upper lip--and present our experience in this report. These lesions appear to behave as transiently 'arterialized' hemangiomas