Good syndrome presenting with multiple pulmonary infections: a case report involving metagenomic sequencing diagnosis

Good syndrome (GS), alternatively termed thymoma with immunodeficiency, is a rare adult-onset immunodeficiency disorder characterized by concurrent thymoma and hypogammaglobulinemia, accompanied by defects in both B-cell-mediated immunity and T-cell-mediated immunity. Owing to the non-specific clinical presentation, diagnosis is frequently delayed, resulting in poor prognosis and elevated mortality. In this study, we report the case of a 69-year-old man with GS who presented with symptoms of recurrent cough and productive sputum. Metagenomic next-generation sequencing (mNGS) of oropharyngeal swabs detected multiple microorganisms, including SARS-CoV-2 (35,047 reads), Epstein-Barr virus (7,236 reads), <i>Micromonas pusilla</i> (3,674 reads), Bacillus spp. (3,284 reads), cytomegalovirus (1,203 reads), and herpes simplex virus type 1 (575 reads). Following a comprehensive clinical evaluation-including recurrent pulmonary infections, history of thymoma, and lymphopenia with immunodeficiency-the diagnosis of GS was confirmed. This patient received an intensified anti-infective regimen, with broad-spectrum carbapenem, meropenem, as the backbone therapy, combined with antifungal agents and antiviral treatment (IV ganciclovir and oral molnupiravir). After aggressive anti-infection therapy, the patient experienced clinical improvement, and chest CT demonstrated significant radiographic improvement. Although intravenous immunoglobulin (IVIG) is foundational in GS, intensive antimicrobial therapy is also critical for clinical outcomes.