A unique microvascular phenotype shared by juvenile hemangiomas and human placenta

Background: Juvenile hemangiomas are common, benign tumors, distinctive for their perinatal presentation, rapid growth during the first year of life, and subsequent involution. We recently reported that endo thelia of hemangi omas highly express GLUT1, a glucose transporter normally restricted to end othelia with blood-tissue barrier function, as in brain and placenta. Objective: To investigate possible further similarities between hemangioma and placental vessels. Design: In a retrospective study of a variety of vascular tumors and anomal ies, we assessed lesional immunoreactivities for the placenta-associated va scular antigens Fc gamma RII, Lewis Y antigen (LeY), merosin, and GLUT1. Setting: A university-affiliated pediatric hospital. Main Outcome Measure: Immunoreactivities scored for each antigen were summa rized according to lesional type, compared with those of normal skin, brain , and placenta, and correlated with patient age, sex, and lesional location . Results: All of 66 hemangiomas (patients aged 22 days to 7 years) showed in tense immunoreactivity for Fc gamma RII, merosin, LeY, and GLUT1. No immuno reactivities for these markers were seen in any of 26 vascular malformation s, 4 granulation tissue specimens, 13 pyogenic granulomas, or in the tumor vasculature of 6 malignant tumors of nonvascular origin. Microvascular immu noreactivity for all 4 markers was observed in placental chorionic villi, b ut was absent in microvessels of normal skin and subcutis. Brain microvesse ls expressed only GLUT1 and merosin. Conclusions: A distinct constellation of tissue-specific markers is uniquel y coexpressed by hemangiomas and placental microvessels. These findings imp ly a unique relationship between hemangioma and the placenta and suggest ne w hypotheses concerning the origin of these tumors.