Rain drop skull appearance is seen: (A) Multiple myeloma, (B) Eosinophilic granuloma, (C) Pagets disease, (D) Sickle cell anemia
Answer is A. Ref. Grainger and Allison's Diagnostic Radiology. Page. 409
 
MULTIPLE MYELOMA –RAIN DROP APPERANCE /PUNCHED OUT LESIONS IN THE SKULL
Imp radiological features –

Expansile osteolytic lesions associated with soft tissue masses
Diffuse osteolysis or generalised osteoporosis
Periosteal new bone formation is characteristically absent
Spine –diffuse lytic lesions