Case Report: Congenital gingival angiomatosis in a newborn lamb

David Zapico^1,2*Victoria Pérez^1,2Miguel Criado Boyero^1,2Pedro Mendívil²Marta Silva^1,2Julio Benavides²María del Carmen Ferreras^1,2José Espinosa^1,2

• ¹University of León, León, Spain
• ²Instituto de Ganaderia de Montana, Vega de Infanzones, Spain

Proliferative vascular disorders are rare congenital tumor-like lesions that arise from anomalies in blood vessel development. A newborn Assaf lamb presented with a diffuse, multinodular, dark-red overgrowth of the periodontal gingiva, accompanied by refusal to suckle. The animal developed diarrhea and died two days after birth. Necropsy was performed, and histopathological examination of the oral lesions revealed a marked expansion of the gingival stroma by multiple, closely packed, small-to medium-sized vascular channels. These were lined by a single layer of von Willebrand factor-and vimentin-positive endothelial cells and were partially surrounded by alpha smooth muscle actin (α-SMA)- and vimentin-positive spindle cells, consistent with well-differentiated capillaries and post-capillary venules. Taken together, these findings were consistent with a diffuse vascular gingival hamartomatosis/angiomatosis. The congenital nature and distribution of the lesions are supportive of a malformation of the periodontal vasculature.