In our study, patients who were consulted to the neurology unit by the thoracic surgery unit in 2021-2022 for possible accompanying MG due to diagnoses of thymic hyperplasia or thymoma were evaluated. Clinical findings of the patients, acetylcholine receptor antibody(AChR-ab) levels and electrophysiological data of repetitive nerve stimulation(RNS) and single fiber electromyography(SFEMG) examinations performed with concentric needle electrode(CNE) were examined.

• No significant incremental response was observed in RNS in any of the 33(13 female, 20 male) patients. In SFEMG performed with CNE, the mean jitter(MJ) increased in 12.1% of the patients. There were MG-related findings in the clinical examination of all patients with increased MJ. AChR-ab was positive in only 1 patient. The pathologies of those who were operated on(63.6%) were thymoma in 42.8%, thymic hyperplasia in 33.3%, thymic cyst in 9.5%, thymic remnant in 9.5%, diffuse large B-cell lymphoma in 4.7%, typical carcinoid tumor in 4.7% and adenomatous nodule in 4.7%. Although no significant relationship was observed between pathological subtypes and electrophysiological findings, the patient with the highest mean jitter value had diffuse large B-cell lymphoma.