Single-stage concomitant extended thymectomy for myasthenia gravis and enucleation of a left recurrent laryngeal nerve schwannoma via median sternotomy.

Abstract

BACKGROUND: Myasthenia gravis (MG) without thymoma is often treated with extended thymectomy to improve symptom control and reduce immunotherapy requirements. Schwannoma of the recurrent laryngeal nerve (RLN) is rare, and surgical resection is usually curative. However, operative manipulation carries a risk of temporary or permanent vocal fold paralysis. When these conditions coexist, choosing staged versus single-stage surgery is non-trivial. A synchronous operation can consolidate perioperative care and recovery but demands careful planning to prevent respiratory complications, particularly if RLN palsy or myasthenic crisis occur. CASE PRESENTATION: A 65-year-old woman with generalized, thymoma-negative MG (acetylcholine-receptor antibody positive) had no hoarseness or dysphagia. Flexible laryngoscopy confirmed mobile vocal folds bilaterally. Chest radiography showed mediastinal widening without diaphragmatic paralysis. Contrast-enhanced CT and MRI revealed a right anterior mediastinal cystic lesion and a solid mass in the left tracheoesophageal groove abutting the RLN. ^18F-fluorodeoxyglucose positron emission tomography demonstrated uptake in the solid lesion (SUV_max 4.89). Transesophageal endoscopic ultrasound–guided fine-needle aspiration yielded spindle cells compatible with schwannoma, and the mass was considered RLN-derived. A single-stage median sternotomy was undertaken. Extended thymectomy was performed with bilateral phrenic exposure and en bloc removal of thymic/perithymic fat, followed by nerve-sparing enucleation of the left RLN tumor through a longitudinal epineurial window and meticulous intracapsular dissection, preserving macroscopic neural continuity. The postoperative intensive care unit course was uneventful: no dyspnea or dysphagia, normal voice, and laryngoscopy confirmed intact vocal fold mobility. A chest radiograph on postoperative day 5 was unremarkable, and the patient was discharged on day 7. Histopathology showed alternating Antoni A/B areas with virtually no mitoses; tumor cells were strongly S-100–positive, confirming schwannoma. CONCLUSIONS: In carefully selected patients with stable MG and no preoperative vocal fold dysfunction, single-stage median sternotomy enables safe concomitant extended thymectomy and RLN schwannoma enucleation. Success hinges on nerve-sparing technique and proactive perioperative planning for airway protection and potential MG crisis.