May Be Caused by

 Common

Breast cancer metastasis

Eosinophilic granuloma

Metastasis

Osteomyelitis

Staphylococcal osteomyelitis

 Uncommon

Congenital cholesteatoma

Dermoid

Fibrosing osteitis

Meningioma

Multiple myeloma

Osteonecrosis of skull

Paget disease of bone

Sarcoidosis

Syphilis

Tuberculosis