Objectives: Chondroblastoma (CB) is a rare, benign but locally aggressive bone tumor. Although the proximal humerus is a common site of involvement, limited data exist regarding its behavior and optimal management. In this study, we report a retrospective series of 26 patients with proximal humerus CB and discuss their management.

Patients & Methods: This retrospective study reviewed 26 cases of histologically confirmed proximal humerus CB treated between 1986 and 2022. Patients underwent either extended curettage (for stage 1 & 2) or en bloc resection (for stage 3). Functional outcomes were assessed using the Musculoskeletal Tumor Society (MSTS) score.

Results: The cohort consisted of 20 males and six females, with a mean age of 16.5 years. The mean follow-up was 11.4 ± 7.9 years. Most lesions were stage 2 (n = 20, 77%). The recurrence rate was 34.6% (n = 9), occurring only in stage 1 and 2 lesions treated with curettage. No recurrences were observed in stage 3 lesions treated with en bloc resection. The average MSTS score was 29.3 ± 0.8 for curettage and 23.7 ± 0.6 for en bloc resection. Complications included restricted active shoulder motion in three patients who were managed with en bloc resection and superficial infection in one who underwent curettage.

Conclusion: Extended curettage for stage 2 chondroblastoma of the proximal humerus carries a high risk of local recurrence. En bloc resection appeared to reduce recurrence in our small cohort, though functional outcomes in this group were lower. Given the limited number of patients treated with en bloc resection, these findings should be interpreted with caution.