Primary vascular neoplasms of the spleen constitute the majority of nonhematolymphoid splenic tumors. The benign primary vascular tumors include hemangioma, hamartoma, and lymphangioma, whereas those of variable or uncertain biologic behavior include littoral cell angioma, hemangioendothelioma, and hemangiopericytoma. The primary malignant vascular neoplasm of the spleen is angiosarcoma. Peliosis is a rare lesion of unknown cause that is usually found incidentally in asymptomatic patients but may be associated with hematologic or metastatic disease.
Although these vascular neoplasms of the spleen are uncommon, their importance lies in that they must be differentiated from the more common neoplastic disorders of the spleen, such as lymphoma and metastasis. The most common echogenic solid or complex cystic mass in an asymptomatic patient is splenic hemangioma. However, the imaging appearance of splenic hemangiomas may be complex, and differentiation of these lesions from malignant disease may not be possible.