littoral cell angioma: a morphologic and immunohistochemical study

littoral cell angioma is a splenic vascular tumor of splenic sinus lining cells that is considered benign in general. this report describes a case of littoral cell angioma with no malignant histological features. the lesion is composed of anastomosing vascular channels resembling splenic sinus; they are lined by endothelial cells which show mitotic activity very rare. immunohistochemically, the tumor cells were positive for both endothelial (factor viii-ag, cd34) and histiocytic markers (kp1 or cd68). the morphologic and immunohistochemical findings in this tumor confirm the presence of dual (endothelial / histiocytic) characteristics of the reticuloendothelial cells lining the splenic sinus, justifying the term littoral cell angioma.