elastin and Bone-Neoplasms

Electron microscopy and both light and electron microscopic immunohistochemical tests for elastin were employed to study the morphogenesis of the unique elastinophilic fibers of an elastofibroma removed from the subscapular region of a 62-year-old woman. Ultrastructurally, as shown by tannic acid stain, elastinophilic fibers of the elastofibroma consisted of central cores and outer zones. The latter were composed of various sizes of vaguely demarcated, irregularly shaped amorphous components and compactly and randomly arranged large amounts of microfibrils. The electron microscopic immunohistochemical results showed that the small-sized amorphous components and microfibrils in the outer zones of the elastinophilic fibers were stained evenly and of granular texture, but the vaguely outlined large amorphous components were not stained. These findings were interpreted as indicating that the amorphous components of the outer zones of elastinophilic fibers were less compact and allowed the penetration of antielastin antibody. The unique elastinophilic fibers of elastofibromas appear not to be formed by the degeneration of the fibers but by abnormal elastogenesis, including an abnormal arrangement of microfibrils.

Topics: Bone Neoplasms; Elastic Tissue; Elastin; Female; Fibroma; Humans; Immunoenzyme Techniques; Microscopy, Electron; Middle Aged; Scapula

A fibroproliferative lesion arising anterior to the lower end of the scapula and containing polymorphic often fiberlike deposits of weakly elastinophilic fibrillary material is described. It is compared on the light and ultrastructural level to a typical elastofibroma. The fibrillary material seen in this tumor strongly resembles that which surrounds the strongly elastinophilic deposits in the typical elastofibroma and from which the elastin is thought to be derived. It is concluded that elastin-producing tumors form a continuum; at one end of which lies the tumor we have designated pre-elastofibroma and at the other, the typical elastofibroma.

Topics: Bone Neoplasms; Elastin; Female; Fibroma; Humans; Middle Aged; Precancerous Conditions; Scapula