May Be Caused by

 Common

Aneurysm

Arteriosclerosis

Arteriovenous malformation

Hemangioma

Hyperparathyroidism

Maffucci syndrome

Mönckeberg medial sclerosis

Phlebolith

Premature atherosclerosis

Varicose vein

 Uncommon

Alkaptonuria

Buerger disease

Calcified thrombus

Cystic fibrosis

Gout

Homocystinuria

Hyperuricemia

Hypervitaminosis D

Hypoparathyroidism

Immobilization

Milk-alkali syndrome

Oxalosis

Pseudoxanthoma elasticum

Radiation therapy

Raynaud disease

Sarcoidosis

Takayasu arteritis

Thermal injury

Widespread bone metastases

Williams syndrome