Malignant endothelial neoplasm arising in the area of lymphangioma: immunohistochemical and ultrastructural observation

Abstract

This report presents a rare malignant endothelial neoplasm which arose at the site of a pre-existing lymphangioma. The lymphangioma was located on the right buccal mucosa, and the malignant neoplasm arose 17 years after irradiation of the initial tumor. Clinical, light microscopic and immunohistochemical (Factor VIII-related antigen and Ulex europaeus Agglutinin-I) studies were made, together with observations by transmission and scanning electron microscopy. These studies provide evidence that this malignant neoplasm was well-differentiated and had not yet lost the characteristics of normal lymphatic cells.