Angiosarcomas of the brain are one of the few primary CNS sarcoma types noted to occur as congenital tumors, but must be distinguished from a rare systemic infantile vascular disorder, diffuse neonatal hemangiomatosis (Fig. 41.1a, b, c). This condition is first recognized at birth or soon thereafter, and is characterized by benign hemangiomas involving three or more organs (Balaci et al., 1999). Skin, liver, lungs, intestines, and CNS are commonly affected sites (Geller et al., 1991), and cases with CNS predilection have been described (Balaci et al., 1999). We have personally seen a case with dramatic CNS involvement (Fig. 41.1a, b).