Severe Aplastic Anemia Following Thymectomy for Thymoma: A Case Suggesting Perturbation of the Adaptive Immune Repertoire.

Aplastic anemia (AA) is an immune-mediated bone marrow failure syndrome. We report a case of severe AA that developed shortly after thymectomy for thymoma. The patient demonstrated monoclonal T-cell receptor β-chain rearrangement and skewed B-cell light-chain expression without evidence of hematologic malignancy. Triple immunosuppressive therapy with horse anti-thymocyte globulin, cyclosporine, and eltrombopag induced rapid hematologic recovery and sustained treatment-free remission. This case expands the clinical spectrum of thymoma-associated aplastic anemia and highlights the importance of recognizing severe AA as a potential complication after thymectomy.