May Be Caused by

 Common

Avascular necrosis

Bone island

Chronic osteomyelitis

Enchondroma

Florid reactive periostitis

Healing fracture with callus

Mycetoma

Steroid medication

Trauma to lunate

Trauma to scaphoid

 Uncommon

Bizarre parosteal pseudotumor

Chondrosarcoma

Connective tissue disease

Enchondromatosis

Ewing sarcoma

Fibrous dysplasia

Gardner syndrome

Healing nonossifying fibroma

Hereditary multiple exostoses

Infarct

Inflammatory arthritis

Intraosseous gouty tophus calcification

Melorheostosis

Osteoblastic metastasis

Osteoblastoma

Osteochondroma

Osteoid osteoma

Osteopathia striata

Osteopoikilosis

Osteosarcoma

Paget disease of bone

Reiter syndrome

Sarcoidosis

Scleroderma

Seronegative psoriatic arthritis

Sickle cell disease

Syphilis

Systemic lupus erythematosus

Tuberous sclerosis

Werner syndrome

Yaws