cavernous hemangioma

n.
  1. A vascular tumor composed of large dilated blood vessels and containing large blood-filled spaces, due to dilation and thickening of the walls of the capillary loops.cavernous angioma
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.