Surgical Result for Patients Who Simultaneously Presented With Myasthenia Gravis and Thymoma.

BACKGROUND

Patients who present concurrently with thymoma and myasthenia gravis (MG) constitute a unique clinical population in whom both oncologic control and stabilization of MG symptoms are essential treatment goals. Although extended thymectomy is traditionally recommended, the necessity of radical thymic tissue removal in this subgroup remains uncertain. This study compared surgical outcomes between thymomectomy and extended thymectomy in this specific population.

METHODS

We retrospectively analyzed 145 patients with concurrent thymoma and MG treated across four tertiary centers between 2013 and 2023. Clinical characteristics, surgical approaches, postoperative complications, MG medication adjustments, and plasmapheresis requirements were compared between patients undergoing thymomectomy (n = 37) and extended thymectomy (n = 108). A 1:1 propensity score matching (PSM) was performed to balance age (n = 37 per group). Freedom from recurrence (FFR) and overall survival (OS) were compared between patients undergoing thymomectomy and extended thymectomy.

RESULTS

Patients undergoing thymomectomy were older with higher anesthesia risk. Despite a higher rate of R1 resections, thymomectomy achieved FFR and OS comparable to extended thymectomy across the entire cohort and within different Masaoka stages. No significant differences were observed in MG medication reduction, plasmapheresis rates, or postoperative MG crisis. Thymomectomy was associated with shorter operative times and avoided the risks related to thymic vein division, a major source of hemorrhagic complications in extended thymectomy.

CONCLUSION

Thymomectomy provides oncologic and neurologic outcomes comparable to extended thymectomy in patients with thymoma-associated MG while reducing operative risks. These findings challenge the necessity of routine extended thymectomy and support thymomectomy as an effective, less invasive alternative in appropriately selected patients.