76 year old man presents with a lytic lesion in the vertebrae. X-ray skull showed multiple punched out lesions. The diagnosis is –

Punched out lesions of skull are seen both in Eosinophilic granuloma and multiple myeloma. However, beveled edges (double contour) is characteristic of eosinophilic granuloma due to uneven destruction of the inner and outer table of the skull.           Punched out lesions of skull                    →  Multiple myeloma           Punched out lesions with beveled edges   →  Eosinophilic granuloma