INTRACRANIAL SUPRASELLAR ANGIOLIPOMA - ULTRASTRUCTURAL AND IMMUNOHISTOCHEMICAL FEATURES

THE AUTHORS PRESENT ultrastructural and immunohistochemical characteri stics of an intracranial suprasellar tumor displaying features of cave rnous angioma with islets of adipose tissue. Electron microscopy revea led thin-walled vessels separated by a loose collagenous stroma contai ning nests of mature adipocytes as well as fibroblasts, myofibroblasts , mast cells, and a few macrophages. Intracytoplasmic lipid droplets w ere also identified in scattered pericytes and smooth muscle cells of vascular walls and in the transitional cells resembling smooth muscle cells and adipocytes. Many adipose tissue cells were positive for S-10 0 protein with polyclonal antibodies. Other lipidized tumor cells were immunoreactive for some or all of the following: smooth muscle-specif ic actin, factor XIIIa, vimentin, and, occasionally, for desmin. Ultra structure and immunohistochemistry indicate that in addition to typica l adipocytes, lipidized cells of another nature contribute to the char acteristic appearance of the adipose tissue component of angiolipoma.