Phalangeal osteoid osteoma.

Although the typical features of osteoid osteomas are well known, those arising in phalanges are frequently misdiagnosed. This is partly because of their rarity (9% of osteoid osteomas in the Bristol Bone Tumour Registry occur in phalanges), and also because of atypical radiological features. The most common appearance is of an eccentric lesion with soft-tissue swelling and a relative absence of sclerosis, suggesting osteomyelitis.