Extracutaneous infantile haemangioma is also Glut1 positive.

AIM To investigate whether extracutaneous infantile haemangioma-like tumours are immunohistochemically similar to cutaneous infantile haemangiomas. METHODS Mammary, salivary gland, liver (one each), and placental (two cases) capillary haemangiomas and typical examples of cutaneous (eight cases) infantile haemangioma were investigated immunohistochemically for alpha smooth muscle actin and Glut1, a proposed marker for the skin localised lesion. Positive internal controls included red blood cells, perineurium, trophoblast, and endothelial cells of the placental capillaries. Extralesional vessel endothelium acted as a negative control (except in the placenta). The liver haemangioma and both chorioangiomas presented in patients with Beckwith-Wiedemann syndrome. RESULTS The endothelial cells of all the vascular lesions were Glut1 positive. These were consistently surrounded by a rim of alpha smooth muscle actin positive pericytic cells. Controls reacted appropriately. CONCLUSIONS All infantile haemangiomas were immunohistochemically positive for Glut1: expression of this molecule was not limited to infantile haemangiomas of the skin. These tumours comprise proliferations of both endothelial and pericytic cells. The association with Beckwith-Wiedemann syndrome may provide a clue to the molecular genetics of infantile haemangioma.