A teenager presenting with pain and popliteal mass

Excerpt

Osteochondromas are a relatively common imaging finding, comprising 20–50% of benign bone tumors [1]. They are often found in metaphyseal regions of long bones, protruding away from the epiphysis [2]. Their appearance is typical on conventional radiographs (Fig. 1), with the main feature being the continuity of the lesion with underlying native cortex and cancellous bone, as well as the presence of a cartilage cap [3], which is best evaluated on MRI (Fig. 2) [2]. The majority of these masses are asymptomatic [2]. The diagnosis is commonly incidental or secondary to related complications, such as fractures, vascular or neurologic compromise, adventitious bursa formation, or malignant transformation [1]. …