Masson's vegetant haemangio-endothelioma.

We present a 14-year-old patient who had a scalp mass that enlarged on dependent positioning. This mass was located in the surgical bed of a previously excised scalp lesion. Valsalva manoeuvre assisted computerized tomography demonstrated this lesion to enhance with contrast and to vary in size. At surgery, a bluish firm mass, located in the galea of the left frontal region, was resected. Total removal resulted in no recurrence at 18 months. Pathological examination revealed a vascular tumour that was first described by Pierre Masson. This is characterized by intravascular vegetations composed of cells of endothelial origin. The exact pathogenesis of these lesions is unknown, but the prognosis based on the review of the literature is expected to be good.