Giant cell tumor of bone most commonly arises in which location?

Explanation

## Location of Giant Cell Tumor **Key Point:** Giant cell tumor (GCT) of bone characteristically arises in the epiphyseal-metaphyseal region (epiphysis extending into metaphysis) of long bones, particularly around the knee joint. ### Typical Sites | Bone | Frequency | Location | | --- | --- | --- | | Distal femur | 20% | Epiphyseal-metaphyseal | | Proximal tibia | 20% | Epiphyseal-metaphyseal | | Distal radius | 10% | Epiphyseal-metaphyseal | | Proximal humerus | 5% | Epiphyseal-metaphyseal | **High-Yield:** GCT occurs almost exclusively in the epiphyseal-metaphyseal region of long bones *after physeal closure* (typically age 20–40 years). This location is pathognomonic and helps differentiate GCT from other bone tumors. **Clinical Pearl:** The tumor extends from the epiphysis into the metaphysis and often reaches the articular surface, making it an intra-articular tumor in many cases. This is why GCT around the knee is the most common presentation in clinical practice. ### Why Epiphyseal Location? The origin is believed to be from stromal cells in the epiphyseal region, which explains the consistent location pattern across all GCT cases.