Splenic lymphangioma with papillary endothelial proliferation: a case report and review of the literature.

A 76-year-old man complained of difficulty breathing. A solitary mass was found in the spleen by ultrasonography and the tumor was excised. Grossly, the tumor was 3.9 x 2.9 cm in size, solid and brownish in color. A stellate scar-like fibrosis was observed in the center of the tumor. Histologically, the tumor consisted of the proliferation of irregular and small lymph vessel-like spaces, with sclerotic change in the center. The lymph vessel-like spaces showed papillary projections of the lining cells. The lumen contained amorphous proteinaceous fluid. Immunohistochemically, the lining cells of lymph vessel-like spaces were positive for endothelial markers (CD31, CD34, factor VIII-related antigen), and bound Ulex europaeus agglutinin-1. The tumor was diagnosed as splenic lymphangioma, but its appearance was rather unusual for a typical splenic lymphangioma because of the presence of papillary endothelial proliferation and scar-like fibrosis. Splenic lymphangioma with papillary endothelial proliferation is uncommon, and there have been only four cases reported.