Abstract
RATIONALE: Good's syndrome (GS) is a rare adult-onset immunodeficiency characterized by the coexistence of thymoma and profound defects in both humoral and cellular immunity. Because of these immune abnormalities, patients are highly vulnerable to recurrent and severe infections, such as COVID-19. However, clinical data on the course and management of COVID-19 in GS remain scarce. This case report aims to describe a patient with recurrent severe COVID-19 following thymectomy and to highlight the diagnostic and therapeutic importance of early immunologic evaluation and intravenous immunoglobulin (IVIG) therapy in this context. PATIENT CONCERNS: A 60-year-old man with a history of thymoma resection presented with recurrent episodes of severe COVID-19 pneumonia, each necessitating hospitalization and oxygen therapy. Despite antiviral and corticosteroid treatment, his condition worsened, with persistent hypoxemia and progressive lung infiltrates. Immunologic workup revealed near-complete B-cell depletion and reduced CD4 + T-cell counts, leading to a diagnosis of GS. DIAGNOSIS: GS following thymoma resection, presenting with recurrent severe COVID-19 complicated by bacterial superinfection. INTERVENTIONS: The patient received antiviral agents, corticosteroids, and broad-spectrum antibiotics across multiple hospitalizations. After diagnosis, IVIG therapy was initiated. OUTCOMES: IVIG administration led to rapid clinical stabilization and marked radiographic improvement. The patient remained free of relapse during follow-up. LESSONS: This case highlights the importance of early immunologic assessment in patients with atypical or recurrent viral infections post-thymectomy. Prompt recognition of GS and initiation of IVIG therapy can be critical to achieving favorable outcomes.