VASCULAR HAMARTOMA OF THE LEFT HALF OF TH E FACE IN A 7 YEAR-OLD THOROUGHBRED STALLION

Hamartomas in the horse have seldom been reported. In this case, a hor se with a massive swelling of the left half of the face is presented. This area had already been operated on al two years oi age. In additio n, a radiation therapy had then been performed. Sonographically, the h orse now shows liquid-filled cavities of varying diameters. A system o f ducts without any connections to blood- or lymph-vessels is shown on the radiographs. This is confirmed pathologo-anatomically. The examin ation of the liquid from the cavities marks it as transsudate. Histolo gy and immunohistology show well-differenciated vessels, mainly withou t. blood cells. The vessels are surrounded by a thick stroma layer. In places, chronic inflammation can be found. Combining these findings, a hamartoma oi the blood-vessel system is diagnosed.