Abstract
Trible‐seronegative myasthenia gravis (tSNMG) is defined as myasthenia gravis (MG) without detectable or low affinity antibodies to acetylcholine receptor (AChR), muscle‐specific kinase (MuSK) andlipoprotein related protein 4(LRP-4). This article reports a case of a 39-year-old married female patient with thymoma-associated seronegative myasthenia gravis (tSNMG), which was accompanied by multiple positive autoantibodies and a benign mediastinal lesion. The primary manifestation was generalized muscle weakness, involving the limbs, bulbar muscles, and respiratory muscles. After admission, the patient showed poor responses to treatments including pyridostigmine bromide, human immunoglobulin, glucocorticoids, and tacrolimus. Ultimately, following therapy with efgartigimod followed by rituximab, significant symptomatic improvement was observed. By analyzing the diagnosis and treatment process of this case alongside relevant literature, this report explores the therapeutic value of efgartigimod followed by rituximab for tSNMG, key points for individualized regimen adjustments, and the challenges in diagnosis and treatment, thereby providing a reference for the clinical management of such refractory cases.