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 endothelia of hemangiomas highly express GLUT1, a glucose transporter normally restricted to endothelia 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 anomalies, we assessed lesional immunoreactivities for the placenta-associated vascular antigens FcgammaRII, Lewis Y antigen (LeY), merosin, and GLUT1. SETTING A university-affiliated pediatric hospital. MAIN OUTCOME MEASURE Immunoreactivities scored for each antigen were summarized 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 intense immunoreactivity for FcgammaRII, merosin, LeY, and GLUT1. No immunoreactivities for these markers were seen in any of 26 vascular malformations, 4 granulation tissue specimens, 13 pyogenic granulomas, or in the tumor vasculature of 6 malignant tumors of nonvascular origin. Microvascular immunoreactivity for all 4 markers was observed in placental chorionic villi, but was absent in microvessels of normal skin and subcutis. Brain microvessels expressed only GLUT1 and merosin. CONCLUSIONS A distinct constellation of tissue-specific markers is uniquely coexpressed by hemangiomas and placental microvessels. These findings imply a unique relationship between hemangioma and the placenta and suggest new hypotheses concerning the origin of these tumors.