What are the two striking features that favor this sole diagnosis.
1. Cartilage cap. 2. Bony outgrowth with preserved cortical continuity.
Bony outgrowth from the posteromedial margin of proximal diaphysis of humerus with preserved cortical continuity. Thin rim of cartilage cap (1.5mm) is seen overlying it. Mild marrow edema seen in subchondral region.