Distribution and Characteristics of Intrathoracic Lymphadenopathy in TB/HIV Co-Infection

Background: Intrathoracic Lymphadenopathy (ITLN) in Human Immunodeficiency Virus (HIV) infected patients may have various etiologies and prognoses. Etiologies of ITLN can be distinguished based on the distribution of enlarged lymph nodes. Sometimes tuberculosis (TB) is the first sign of underlying HIV infection. Objectives: We sought to determine ITLN distribution and associated pulmonary findings in TB/HIV co-infection using Computed Tomography (CT) scan. Methods: In this retrospective, observational, cross-sectional study, chest CT scans of 52 patients with TB/HIV co-infection were assessed for enlarged intrathoracic lymph nodes (>10 mm in short axis diameter), lymphadenopathy (LAP) distribution, calcification, conglomeration, the presence of hypodense center and associated pulmonary abnormalities. LAP distribution was compared in TB/HIV co-infection with isolated TB infection. Results: Mediastinal and/or hilar LAP were seen in 53.8% of TB/HIV co-infection patients. In all cases, LAP was multistational. The most frequent stations were right lower paratracheal and subcarinal stations. Lymph node conglomeration, hypodense center and calcification were noted in 25%, 21.4% and 3.5% of patients, respectively. LAP distribution was the same as that in patients with isolated TB infection except for the right hilar, right upper paratracheal and prevascular stations. All patients with mediastinal and/or hilar adenopathy had associated pulmonary abnormalities. Conclusion: All patients with TB/HIV co-infection and mediastinal and/or hilar adenopathy had associated pulmonary abnormalities. Superior mediastinal lymph nodes were less commonly affected in TB/HIV co-infection than isolated TB.