Chondroblastoma of the Proximal Humerus in a 12-years-old Female: A Case Report and a Review of the Literature.

Introduction: This case is important because it highlights a rare presentation of chondroblastoma, given the tumor's male predominance and its uncommon occurrence in females. The proximal humerus is one of the less frequently reported sites for chondroblastoma, additionally, the tumor exhibited aneurysmal changes, a known risk factor for recurrence. This case contributes to the orthopedic literature by providing insight into the clinical and imaging features, challenges in diagnosis, and management strategies for this rare tumor.

Case report: A 12-years-old girl from México, presented with progressive right shoulder pain after a traction injury, clinical examination showed limited abduction and a palpable mass, imaging and pathology tests revealed a lesion in the proximal humerus. Due to the tumor's extent, en bloc resection with an allograft and fixation was performed, a procedure not commonly used in these patients, to restore morphology and function.

Conclusion: This case underscores the importance of early recognition and a multidisciplinary approach to managing chondroblastoma, especially in atypical presentations, such as in young females. En bloc resection combined with allograft reconstruction provided a favorable clinical outcome, minimizing recurrence risk and preserving joint function. This report contributes to the orthopedic literature by documenting a rare presentation and emphasizing the critical role of individualized surgical strategies and post-operative rehabilitation in achieving optimal outcomes.