Infantile hemangioendothelioma of the liver: ultrastructural study of a type II case

A case of infantile hemangioendothelioma of the liver presenting with congestive heart failure and massive hepatomegaly in a two-mth old baby is described. Serum alpha-fetoprotein was elevated in this patient and clinically the lesion might not be distinguishable from other, commoner hepatic tumours in children. Histologically the tumour showed a type II pattern as defined by Dehner. The significance of classifying this tumour into two histologic types is discussed. Only 3 cases reported in the English literature were studied by electron microscopy; two of them were type I while the other was a type II lesion. In our case the endothelial cells appeared ultrastructurally less differentiated and architecturally more disorganized than in type I lesions. Like the previous case, the basal lamina showed marked thickening and reduplication. The significance of these findings is discussed.