<prompt> A 56-year old man presented with bony pain. X-ray skull lateral view shows:Pagets diseaseHyper osteosis frontalisFibrous dysplasiaOsteopetrosis  <response>: Ref. Grainger and Allisons Diagnostic Radiology. Page. 483 Pagets disease of bone affects each person differently . It includes :1 Bones : Pain in the affected bones is the most common symptom of pagets disease of bone. Skull in Pagets disease osteoporosis circumscripta: large, well-defined lytic lesioncotton wool appearance: mixed lytic and sclerotic lesions of the skulldiploic widening: both inner and outer calvarial tables are involved, with the former usually more extensively affectedTam oShanter sign: frontal bone enlargement, with the appearance of the skull falling over the facial bones, like a Tam o Shanter hat 