Fibrous Dysplasia
A benign skeletal developmental anomaly in which normal medullary bone is replaced by fibrous tissue with irregularly shaped woven bone trabeculae in a 'Chinese-character' pattern, caused by somatic GNAS mutations.
Full Definition
Fibrous Dysplasia is a non-inherited skeletal condition resulting from activating somatic mutations in the GNAS gene, leading to replacement of normal cancellous bone with fibrous connective tissue interspersed with curvilinear woven bone trabeculae classically described as resembling Chinese characters or alphabet letters. In the craniofacial skeleton it can occur as a monostotic lesion affecting a single bone or as part of polyostotic disease, the latter sometimes associated with McCune–Albright syndrome. On imaging it produces a characteristic 'ground glass' radiodensity. Editors must not equate this with ossifying fibroma, which is encapsulated and surgically distinct; the absence of a capsule and the fading radiographic border are key distinguishing features that should be preserved in edited text.
Usage
Usage note: Always distinguish monostotic from polyostotic forms when context requires it. Do not hyphenate ('fibrous dysplasia,' not 'fibrous-dysplasia'). Avoid shortening to 'FD' in clinical editorial text without expansion.
In Context
- "Radiographic findings of ground-glass opacity with an ill-defined border supported a diagnosis of fibrous dysplasia rather than ossifying fibroma." — Radiology–Pathology Correlation Report
- "The copy-editor corrected 'fibrous-dysplasia' to 'fibrous dysplasia' in accordance with standard nomenclature." — Textbook Chapter