Lymphangioma of the duodenum: an ultrastructural study.

Two cases of duodenal lymphangioma were diagnosed by endoscopy, and light and electron microscopic findings are reported. Ultrastructural studies showed smooth muscle cells around lymphatic vessels, and amyelinic nerve fibers and smooth muscle cells in the interstitium. On the basis of the ultrastructural features, a hamartomatous rather than tumoral origin is suggested for the duodenal lymphangioma. Lymphangiectatic cysts of Letulle and lymphangiectasia are discussed in the differential diagnosis. Submucosal lymphangiomas of the small bowel might be considered lymphangiectatic cysts.