Mesenteric lymphangioma. A case report with transmission and scanning electron microscopic studies.

A mesenteric lymphangioma was found in a 2-day-old newborn, thus attesting to the congenital nature of the lesion. The ultrastructural features of the tumor included a poorly developed, discontinuous basal lamina, and anchoring fibrils distinguished it from a hemangioma. An undulating surface of the endothelium and prominent grooving between the endothelial cells were found by scanning electron microscopy and were indistinguishable from arterial and lymphatic endothelial surfaces that have been studied by others.