Beyond Good’s syndrome: A case of multifactorial thymoma-related immunodeficiency with cytomegalovirus reactivation

Introduction: Thymomas, by virtue of T-cell maturation derangement, are frequently accompanied by parathymic syndromes. Classically, Good’s syndrome characterizes immunodeficiency in patients with thymoma, comprising of hypogammaglobulinemia and various degrees of T-cell impairment; however, these patients frequently suffer from additional iatrogenic effects of chemotherapy or immunosuppressors used to control autoimmune phenomena. As a result, they often exhibit signs of decreased bone marrow response and cytopenias, leading to opportunistic infections such as cytomegalovirus (CMV) reactivation, whose role in perpetuating the state of immunodeficiency may be under-explored. Case Report: We describe the case of a 62-year-old man with a thymoma who exhibited several paraneoplastic syndromes, including Good’s syndrome. The patient had also been diagnosed with sigmoidal adenocarcinoma, previously medicated with capecitabine and was currently medicated with corticosteroids and azathioprine, placing an additional strain on his already compromised immune system. After being inadvertently exposed to the combination of azathioprine and allopurinol, he developed pancytopenia with little response to granulocyte-colony stimulating factor (G-CSF) after withdrawal of the offending agents. A high CMV viral load was suspected as a cause for perpetuating leukopenia. Treatment with ganciclovir resulted in bone marrow recovery, and immunoglobulin replacement together with antibiotic and antiviral prophylaxis prevented other serious infections until thymectomy and completion of chemotherapy. Conclusion: This case exemplifies many of the complexities in managing patients with thymomas, particularly when balancing autoimmunity and immune suppression. Cytomegalovirus reactivation is not unusual in this context and cytopenias may be the only manifestation. Although treatment of symptomatic disease is beneficial, the role of prophylaxis is not yet consensual due to its potentially myelosuppressive effects.