Ultrasound-guided percutaneous microwave ablation of splenic solid lesions: experience in a rare cohort.

PURPOSE: To investigate the feasibility, safety, and efficacy of ultrasound-guided percutaneous microwave ablation (MWA) for splenic solid lesions. MATERIALS AND METHODS: A total of 34 patients with 42 splenic tumors who underwent MWA between October 2006 and April 2025 were enrolled in this retrospective study. The primary endpoints were technical success rate, tumor volume reduction rate (VRR), and local tumor progression (LTP) rate. Secondary endpoints included overall survival (OS) and complication rate. RESULTS: The overall cohort was divided into a primary benign group (n = 15) and a secondary malignant group (n = 19), achieving the total technical success rate of 100% across all lesions. In the primary benign cohort, 66.7% (10/15) of patients achieved tumor VRR over 80% at one year, and the median OS was not reached (all patients remained alive). In the secondary malignant cohort, 68.4% (13/19) showed tumor VRR over 80% at one year, with a median OS of 114 months. Four patients with malignant lesions developed LTP, and received repeated ablation. The most common complication was thrombocytopenia which resolved without intervention. CONCLUSION: This study provides preliminary evidence that ultrasound-guided percutaneous MWA is a feasible and relatively safe approach for reducing splenic solid lesion burden while preserving spleen in selected patients.