A male newborn has a hemangioma on the left frontotemporal region of his face and scalp. The cells forming the hemangioma are derived from which of the following cell layers?

B. A hemangioma is a vascular tumor that can be present at birth in which the abnormal proliferation of blood vessels leads to a mass resembling a neoplasm. Hemangiomas are mesodermal in origin, in that they are formed by embryonic blood cells and the vascular endothelium formed by angioblasts.