Clinical Relapse of Anti-AMPAR Encephalitis Associated with Recurrence of Thymoma

We report a rare case of anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) encephalitis presenting clinical relapse in association with recurrence of thymoma. Anti-AMPAR encephalitis is an autoimmune-mediated neurological disease, frequently accompanied by the presence of neoplasms, thus comprising the spectrum of paraneoplastic syndrome. A patient had been in remission for 34 months showed clinical relapse 3 months after the detection of recurrent thymoma. Clinical relapse of anti-AMPAR encephalitis after the recurrence of an initially detected neoplasm has not been previously reported. Our case therefore highlights the pathogenic relevance of specific tumor antigens as a trigger of anti-AMPAR antibody production and induction of the disease.