[A rare tumour of the orbit in a child (author's transl)]

The authors present an observation on a rare tumour of the orbit in an 8-years-old boy, revealed by a right unilateral exophtalmia with visual disturbances. This tumour poses the problem of the differential diagnosis of a localized osteolysis; in spite of the arsenal of investigations, the final diagnosis was laid down only upon intervention and histological examination: it was a case of a malignant haemangioendothelioma. The interest of the observation lies in:--the rarity of this type of tumour; --the complete nature of the observation, describing the course of events and the difficulties of diagnosis as well as the fatal evolution despite the surgical and radiochemotherapy treatments.