[Malignant xanthogranuloma of the cervicofacial region. Optical and ultrastructural morphology. Apropos of 4 cases].

The 4 cases of malignant xanthogranuloma reported here are peculiar because of their unusual localization in the cervico-facial area and of their good outcome (3 patients are alive without recurrence more than 6 years after chemotherapy and radiotherapy). Besides the histological study, the 4 cases were examined by immunohistochemical methods : vimentin was positive in 20 to 40% of cells and lysozyme in 5 to 15% of cells. In addition, one case was studied by electron microscope which showed the polymorphism of tumoral cells.