Severe Mycoplasma-Induced Mucositis and Granulomatous-Lymphocytic Interstitial Lung Disease as Initial Manifestations of Common Variable Immunodeficiency in a Young Adult

Granulomatous-lymphocytic interstitial lung disease (GLILD) is a severe, non-infectious, and rare pulmonary complication of Common Variable Immunodeficiency (CVID), characterized by lymphocytic infiltrates and/or granulomas in the lung. We present the case of a 20-year-old male with recurrent, steroid-responsive hypoxemia and interstitial lung disease, initially attributed to sarcoidosis. Further evaluation revealed hypogammaglobulinemia and autoimmune cytopenias, with imaging demonstrating a steroid-responsive, waxing–waning perilymphatic nodularity and histopathologic findings consistent with GLILD. Interstitial lung disease (ILD) is infrequently the initial manifestation of CVID, and patients may not always have a history of recurrent pulmonary infections prior to diagnosis. Sarcoidosis is a common differential diagnosis for GLILD, as it may present similarly, but key radiological and histopathological features allow for accurate distinction.