Histomorphometrical study in cavernous lymphangioma of the tongue

OBJECTIVE: To study the histomorphometrical characteristics of lymphatic vessels in cavernous lymphangiomas of the tongue. MATERIAL AND METHODS: Immunohistochemical stainings were prepared in the 20 specimens with three antibodies [D2-40, CD31 and proliferating cell nuclear antigen (PCNA)]. Three-dimensional (3D) reconstruction and histometrical analysis of the lymphatic vessels was also examined. RESULTS: Distinctly positive staining for D2-40 was found in dilated lymphatic vessels located in the lamina propria beneath the thinned covering epithelium. Small blood vessels stained positively for CD31 were present in the lamina propria. PCNA-positive lymphatic endothelial cells were scattered in both control and lymphangioma. The 3D architecture of lymphatic vessels was characterized by a complex network with irregular branches in the lamina propria. Histometrical analysis showed that the number of lymphatic endothelial cells per lymphatic vessel perimeter in cavernous lymphangioma was significantly higher than that in control. There were no significant differences in the lymphatic density and the ratio of PCNA-positive lymphatic endothelial cell nuclei to the total number of lymphatic endothelial cell nuclei between control and lymphangioma. CONCLUSIONS: These results indicate the absence of excessive endothelial cell proliferation in dilated lymphatic vessels in cavernous lymphangioma. Cavernous lymphangioma may be attributed to the enlargement of lymphatic vessels without the tumorous proliferation of lymphatic endothelial cells.