Surgical approach and tumor size influence outcomes in thymoma: a retrospective analysis of 70 cases.

BACKGROUND

Minimally invasive surgery (MIS) has become increasingly applied in thymoma, but its feasibility for large tumors remains contested.

METHODS

We retrospectively reviewed 70 patients, treated between 2001 and 2023, with Masaoka stage I-II thymomas. Patients were stratified according to surgical approach-open surgery (OP, n = 20) or MIS (video- or robot-assisted, n = 50)-and tumor size using both preoperative CT and specimen measurements with 5- and 6 cm thresholds. Perioperative outcomes were compared using propensity score matching (PSM).

RESULTS

MIS was associated with less intraoperative blood loss, shorter drainage duration, and shorter hospital stay compared with OP, without conversions to OP. These benefits persisted after PSM. The use of MIS gradually expanded to include tumors ≥ 5 cm, with perioperative outcomes improving in a later phase. Within the MIS cohort, tumor size ≥ 5 cm did not significantly affect operative time, blood loss, or recovery. Exploratory analyses using a 6 cm cutoff showed comparable overall outcomes. Oncologic events were rare, with only one recurrence observed in the entire cohort.

CONCLUSIONS

MIS offers superior short-term perioperative outcomes compared with OP and appears feasible for selected patients with large thymomas. However, its long-term oncologic validity-particularly regarding pleural dissemination and late recurrence-requires confirmation in multicenter prospective studies.