Pathology of a Calf Diagnosed with Bovine Juvenile Angiomatosis Characterized by Multiple Vascular Hamartomas in the Skin and Gingiva

Abstract

Multiple masses appeared in the skin of the right foot and the oral cavity of a two-month-old crossbred calf that had exhibited swelling in the right tarsal region from birth. The sizes of the cutaneous and gingival masses were from 0.5 to 3 cm in diameter and they were white in color and edematous at their cut surfaces. Histopathologically, each mass was composed of numerous various-sized mature blood vessels lined with a single layer of endothelial cells. The endothelial cells had enlarged nuclei without atypia or mitosis. Mucin production and loose fibrous connective tissue were observed in the stroma. This case was diagnosed as bovine juvenile angiomatosis, since the histopathological features resembled vascular hamartoma, and the masses were seen in multiple sites in the calf. This is the first report of bovine juvenile angiomatosis in Japan.