History (HX): Pain and palpable bony prominence .

male 29y

Findings: A small well-defined lesion within the cortex of distal humeral diaphysis with surrounding cortical hyperostosis, a small central nidus, bone marrow edema and perilesional soft tissue edema.

Diagnose (DX):Osteoid osteoma

Discussion: Benign tumor consisting of osteoblastic mass (nidus) surrounded by zone of reactive sclerosis