Pulmonary metastasis in chondroblastoma: An institutional cohort and meta-analysis.

Abstract

e23506 Background: Chondroblastoma is a benign bone tumor with rare potential for pulmonary metastasis. The true incidence of lung metastasis remains uncertain due to inconsistent surveillance practices. We sought to determine the rate of pulmonary metastasis in chondroblastoma and characterize current chest imaging practices using an institutional cohort and literature meta-analysis. Methods: We conducted a retrospective review (2010-2025) of 19 chondroblastoma patients at our institution and stratified them by whether chest imaging was obtained. A meta-analysis of 23 published studies comprising 411 chondroblastoma patients was also conducted. Primary outcomes were pulmonary metastasis and mortality. Imaging utilization and clinical characteristics were compared between cohorts. Results: Sex distribution was nearly identical between both groups (institutional 62.3% male vs literature 65.9% male, p = 0.994). The mean age of the institutional cohort was 18.6 ± 5.5 years. Pulmonary metastasis was identified in 1 of 19 institutional patients (5.3%) and in 23 of 411 patients from the literature (5.6%), with no difference between cohorts (p = 1.000). Chest imaging was performed in 42.1% of institutional patients and reported in 47.8% of literature cohorts (p = 0.82). Imaging was performed for routine staging in 87.5% of institutional cases and 63.6% of literature cases (p = 0.338). Among imaged patients at our institution, median tumor size was larger compared with non-imaged patients (3.66 vs 2.20 cm), approaching statistical significance (p = 0.077). The median time from diagnosis to chest imaging was 145 days at our institution. No institutional patients had lung metastasis at initial presentation compared with 3.41% reported in the literature (p = 1.000). All institutional patients were alive and disease-free at last follow-up, and only 3 cases of disease-specific mortality were reported in the literature (0.73%). Conclusions: Although exceedingly rare, lung metastasis in chondroblastoma does occur. Current surveillance practices for chondroblastoma metastasis are inconsistent and lack standardization. Despite metastasis detection, prognosis remains excellent, with only three reported cases in the literature resulting in mortality. These findings suggest that implementing image surveillance may be needed to better define true metastasis rates and guide optimal management strategies.