Vascular malformations of the central nervous system are thought to originate from abnormal developmental processes during embryogenesis. Reports have cited the dynamic nature of these lesions and their “maturation” into other types of malformations. Herein we report on three patients with vascular malformations who exhibited dynamic alterations with stepwise progression of their lesions. These cases lend support to the hypothesis that these malformations may constitute the spectrum of a single disease caused by alterations in a common developmental program and that accumulating injury (e.g., by radiation) may allow one malformation type to mature into another. This concept warrants further investigation.