Paraneoplastic neurological autoimmunity associated with ANNA-1 autoantibody and thymoma

Neurologic autoimmunity frequently occurs with thymoma, particularly myasthenia gravis and skeletal muscle-specific autoantibodies. Type 1 antineuronal nuclear antibody (ANNA-1/"anti-Hu"), which is recognized as an immunoglobulin G marker of small-cell lung carcinoma, has not been reported with thymoma. The authors identified four patients (three under age 40) with ANNA-1 and a paraneoplastic neurologic complication of thymoma. Retrospective testing of stored serum from 172 patients with thymoma revealed ANNA-1 in 3%. This report extends the oncologic implications of ANNA-1 seropositivity.