Thymoma with immunodeficiency/Good syndrome associated with myasthenia gravis

Good syndrome is a rare condition in which thymoma is associated with hypogammaglobulinemia; it is characterized by repeated respiratory or systemic infections caused by bacteria, viruses, and fungi, as well as with various autoimmune disorders such as pure red cell aplasia. A 65-year-old woman was admitted to our hospital with ptosis and abdominal muscle weakness. Based on the presence of anti-acetylcholine receptor (Ach-R) antibodies, she was diagnosed with myasthenia gravis (MG). At that time, invasive thymoma of Masaoka stage IVa was also detected. Regression of thymoma and clinical remission of MG was achieved by chemotherapy followed by high-dose corticosteroid. However, several months later, the patient started developing repeated bacterial respiratory tract infections, cytomegalovirus infections, and esophageal and systemic candidiasis. Laboratory tests revealed a marked decrease of serum gamma-globulin levels (IgG 586 mg/dl, IgA 32 mg/dl, IgM 29 mg/dl) and severe reduction in the B cells ratio, as well as a decrease in the CD4+CD25+T cell to CD4+CD25-T cell ratio indicative of deregulation of CD4+T cell activation. These results suggested that the patient impaired humoral and cell-mediated immune responses. We continued the treatment with antibiotics and regular immunoglobulin supplementation through intravenous injections. Although autoimmune disorders are often observed in Good syndrome, the association with MG is quite rare. The case report is followed by the review of literature.