This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Tumors, Subject name: Orthopaedics
Characteristic radiological feature of fibrous dysplasia- 
Select and explain. 
A. Thickened bone matrix, B. Coical erosion, C. Ground glass appearance, D. Bone enlargement
C: Ground glass appearance
Answer: C: Ground glass appearance 
Explanation: Fibrous Dysplasia (FD) Asymptomatic, self-limiting developmental regional alteration of bone in which the normal architecture is replaced by fibrous tissue and nonfunctional trabeculae-like osseous tissue. It is self-limiting (thus it is not a true neoplasm) * Represents a group of disorders with variety of clinical patterns * Mutation in GNAS 1 gene Clinical forms of fibrous dysplasia of the jaws * Monostotic: localized to a single bone Juvenile and aggressive juvenile Adult * Polystotic: involves several bones Craniofacial McCune-Albright syndrome Jaffe syndrome ref " maheswari 9th ed