Fibrous and Granulomatous Compartments in the Otosclerotic Focus

BESIDES the two basic forms of bone in the otosclerotic focus, produced by metaplasia (the spongious and the sclerotic), a third, less conspicuous component appears represented by spaces surrounded by bone or bordering on lumina of the inner meatus and the cochlea. They are filled by fibrous or granular material, a loose network of delicate fibers that occasionally show cystic arrangement; granulation tissue is suggested. Although known for a long time, this has been granted only a fleeting attention. Connective tissue areas have been described with scarce bony spicules as the result of regression or dystrophy.1 "Younger" otosclerotic tissue has been characterized as constructed of lamina enclosing in their mesh a mass rich in cells, frequently similar to granulation tissue were it not for a relative paucity in cells; the essential product is a combination of osseous with fibrous tissue.2"Cysts" with extravasated blood have been described in