Crystalline lamellae in the endothelial cells of a type of hemangioma characterized by the proliferation of immature endothelial cells and pericytes--angioblastoma (Nakagawa).

Two babies were found to have large hemangiomas. Histologically there were many islands of compactly packed mesenchymal cells in the deep dermis and subcutaneous tissue. Electron microscopically there was proliferation of immature endothelial cells and pericytes. Characteristic crystalline lamellae were in the endothelial cells. Our two cases seemed to be an independent entity from other benign angiomas because of the distinct clinical, histologic, and ultrastructural features. The suggested diagnosis was angioblastoma (Nakagawa; Miki and Matsumoto), hypertrophic hemangioma (Watson and McCarthy), and benign hemangioendothelioma (Stout).