exostosis

Pronunciation key ( ek′sos-tō′sis ) ( ek′so-stō′sis )

ex•os•to•sis

n. [pl. EXOSTOSES (-sēz) exosto′ses.]

[Mod. L.; Gr. exostōsis < ex- outside + osteon, a bone].

1. Pathology, Medicine. Abnormal, yet benign tumor or new bony growth on either inner or outer surface of a bone or tooth. Characteristically capped with cartilage.
2. A morbid formation and protuberance of bone. Morbid bony growth on a bone.
3. Formation of knots on trees.

Adj. exostot′ic. See Osteochondroma.

exostosis cartilagin′ea, a variety of osteoma consisting of a layer of cartilage developing beneath the periosteum of a bone.

hereditary multiple exostosis, a generally benign, hereditary disorder of enchondral growth of bone, marked by extoses near the extremities of the diaphysis of long bones.

References

The American College Dictionary (Random House) ©1949

Webster's New World Dictionary of the American Language (College Edition) ©1955

Webster's Improved Dictionary and Everyday Encyclopedia ©1956

Funk and Wagnalls Standard Dictionary, Comprehensive International Edition ©1976

Encyclopedia and Dictionary of Medicine, Nursing and Allied Health ©1978

Encyclopedia Britannica Micropedia ©1984

The American Heritage Dictionary, Second College Edition ©1985