In this location (middle third of the tibia) which two other entities (which may or may not be related to each other) can be indistinguishable from fibrous dysplasia?
Osteofibrous dysplasia and adamantinoma (although ground glass opacity is usually not present in the latter).
What two main forms of fibrous dysplasia are recognised and what is the proportion of each?
Monostotic (70-80%) and polyostotic (20-30%).
A lytic lesion is demonstrated in the left lower tibial diaphysis with ground-glass appearance, endosteal thinning of the cortex, and some ballooning of the shaft. No periosteal reaction is seen.