A Clinicopathologic Study of lnfanti le Hemangioendothelioma of the Liver

= A bs t rac t = Infantile hemangioendothelioma which is the most common primary vascular neoplasm of the liver in infancy and early childhood, frequently poses diagnostic problems due to its characteristics, and thus the authors performed a retrospective clinicopathological analysis of 5 cases of infantile hemangioendothelioma of the liver. All the cases were found before 6 months of age, and there were two females and three males. An abdominal mass and jaundice comprised main symptoms, and associated cutaneous hemangiomas were not present. A case had features of Kasabach-Merritt syndrome. The tumors were well circumscribed, solid masses with areas of necrosis and hemorrhage, and microscopically were composed of numerous vascular channels of varying size, separated by fibrous stroma containing a single layer of flat or plump endothelial cells which were located on the luminal side of the vascular reticulin sheath. Immunohistochemical staining demonstrated factor VIII-related antigen in the tumor cells, and ultrastructurally, relatively well formed vascular lumina were surrounded by sparsely arranged elongated spindle cells having parallel processes. Among the divergent primary hepatic neoplasms in infancy and childhood, this tumor was found to have rather distinct clinicopathological features, and the detailed differential points from other types of neoplasm were discussed along with its anticipated biologic behaviour.