Lymphangiomas are usually congenital or arise in young children. They are thought to be congenital malformations of lymphatic vessels, however, a subset of them may be acquired due to lymphatic obstruction (e.g. trauma, infection, surgery).

Abdominal lymphangiomas are rare, and these can arise in the mesentery, GI tract, retroperitoneum, pancreas and liver (Allen).

Histologically, LM is composed of variably-sized vascular spaces lined by endothelial cells. Rare RBCs may be seen within the lumina. The vessel walls may contain smooth muscle, fat, nerve fibers and lymphoid aggregates. Foam cells and cholestrol clefts may be seen as well.

It may be difficult to distinguish lymphangiomas from a hemangioma as both entities are lined by endothelial cells and may contain RBCs. However, the presence of lymphoid aggregates, foam cells, cholesterol clefts and adipose tissue favors LM. Furthermore, the endothelial cells in LM will stain for D2-40, whereas D2-40 would be negative in a hemangioma.

Other entities on the differential include angiomyolipoma (exhibits thick-walled vessels and HMB45 positivity), mesenteric cyst (less complex than lymphangiomas and either have no lining or lined by cuboidal or columnar epithelium), benign multicystic peritoneal mesothelioma (CK5/6 and calretinin positive, no lymphoid tissue in the stroma).

Although benign, abdominal lymphangiomas can invade surrounding structures, causing significant morbidity (obstruction, abdominal pain, distention) necessitating large and potentially hazardous resections (Allen. Chen).