[Congenital haemangiomas and other rare infantile vascular tumours]

A number of infantile tumours, far less frequent than infantile haemangiomas, were long assimilated to them. Today they are clearly individualised, based on distinctive clinical and pathologic features, and this difference has been supported by the discovery of new immunophenotypic markers such as GLUT1. GLUT1 stains 100% of infantile haemangiomas and none of the other infantile vascular tumours. Congenital haemangiomas represent a group of vascular tumours still under evaluation as they have slightly heterogeneous presentation. Their prognosis is better appraised and their therapeutic management has improved. They are all fully grown in utero and they do not experience postnatal proliferation like haemangiomas do. Some of them (RICH--Rapidly Involuting Congenital Haemangioma) undergo spontaneous involution during the first year. Others (NICH--Non Involuting Congenital Haemangioma) persist lifelong. Tufted angioma and kaposiform haemangioendothelioma are histopathologically well characterized; in addition they are now considered as part of a same spectrum of vascular tumours, with the contribution of lymphatic endothelial cells in their proliferation. Both are clearly the tumours able to create platelet trapping, thrombocytopenia and the life-threatening Kasabach-Merritt syndrome. However they may occur as isolated tumours, without thrombocytopenia but with cosmetic, and sometimes function-impairing, consequences.