Capillary hemangioma of the central nervous system: a comparative study with lobular capillary hemangioma of the skin.

Capillary hemangiomas have rarely been reported to develop in the brain or spinal cord. Here we report the histological and immunohistochemical features of ten cases of central nervous system capillary hemangiomas (CNSCH) and compare these to those of lobular capillary hemangioma (LCH) of the skin. CNSCH showed a lobular architecture with lobules that were separated by fibrous tissue septa in six cases. The lobules were composed of numerous, tightly packed, capillary-sized vessels. A highly cellular area was seen in six cases. A blood-filled cavernous space and fibroendothelial papillae that mimicked papillary endothelial hyperplasia were seen in four cases. Stromal edema was observed in nine cases. These features were not statistically different from those of LCH of the skin, although the highly cellular area was more prominent and more frequent in cases of CNSCH. Immunohistochemical studies demonstrated no positive staining of endothelial cells within either lesion for erythrocyte-type glucose transporter protein, which is a selective marker for capillary hemangioma of infancy. Vascular endothelial growth factor immunostaining demonstrated positive cells in the solid or immature-appearing areas without vessel lumen formation in both lesions. Some of the endothelial cells and stromal cells were positive for glucocorticoid receptor immunostaining. The MIB-1 index of CNSCH was variable (mean 5.6%) and the apoptotic index of CNSCH was significantly lower than that of LCH of the skin. CNSCH are benign lesions with histological and immunohistochemical features similar to those of LCH of the skin.