Please tell me what are benign tumours encapsulated in?

Surrounding cells: All benign tumours tend to remain localized at the site of origin. Most are enclosed by a capsule consisting of fibrous connective tissue derived from the structures in which the lesion is growing and for which the tumor has compressed but not invaded. Well-encapsulated tumors enlarge by a gradual buildup of cells , pushing aside the adjacent tissues without involving them. As such they grow as well-defined masses that displace the normal cells out of the way rather than invading surrounding tissue;