Introduction

Common variable immunodeficiency (CVID) is the most common symptomatic primary antibody deficiency in adults and is characterized by hypogammaglobulinemia, impaired antibody production, and recurrent bacterial infections [1,2]. It comprises a heterogeneous group of disorders with variable clinical manifestations, ranging from recurrent infections to autoimmune diseases, granulomatous inflammation, lymphoproliferative disorders, and malignancies, making the diagnosis particularly challenging [1,3].

Although CVID is a primary immunodeficiency, its diagnosis is frequently delayed because of its heterogeneous presentation and the absence of specific clinical features during the early stages of the disease. Previous studies have reported a median diagnostic delay ranging from approximately four to nine years, a delay associated with an increased risk of irreversible organ damage, chronic pulmonary complications, and immune dysregulation [4,5]. Most patients are diagnosed between the second and fourth decades of life; however, some individuals remain undiagnosed until late adulthood, particularly when recurrent infections are initially considered isolated events rather than manifestations of an underlying immune disorder [2,4,5].

Respiratory tract involvement is the most common clinical manifestation of CVID and represents the leading cause of morbidity and mortality. Recurrent sinopulmonary infections, chronic bronchitis, pneumonia, bronchiectasis, pulmonary nodules, and granulomatous-lymphocytic interstitial lung disease are frequently encountered [1,4,6]. In addition to infectious complications, approximately one-third of patients develop non-infectious manifestations, including persistent lymphadenopathy, splenomegaly, autoimmune diseases, and granulomatous lesions that may mimic sarcoidosis, tuberculosis, or lymphoproliferative disorders, often leading to extensive investigations before the diagnosis of CVID is established [3,7,8].

Persistent generalized lymphadenopathy is a recognized but often misleading manifestation of CVID. Histopathological examination usually reveals reactive follicular hyperplasia or benign lymphoid proliferation, making the exclusion of lymphoma and chronic infections mandatory [7,8].

We report a case of delayed diagnosis of CVID in a 57-year-old woman presenting with recurrent respiratory infections associated with persistent mediastinal lymphadenopathy. This case highlights the importance of considering CVID in adults presenting with recurrent respiratory infections and unexplained persistent lymphadenopathy, even in the absence of a previous history suggestive of immunodeficiency.