Atypical Radiological Presentations of Pulmonary Tuberculosis: An Analysis of Associated Factors

Abstract

Background: Pulmonary tuberculosis (PTB) classically demonstrates typical radiographic features of upper-lobe cavitation and consolidation. Yet, in particular populations, atypical radiographic presentations are seen that can mimic other pulmonary diseases and make diagnosis challenging. Knowledge of the factors related to atypical presentations is essential to enhance early detection and treatment. Objective: To study the demographic, clinical, immunological, and microbiological factors related to atypical radiologic presentations in patients with pulmonary tuberculosis. Methodology: This cross-sectional analytical study comprised 260 patients with microbiologically confirmed PTB. Radiographs of the chest and CT scans were interpreted by experienced radiologists and results were classified into typical (n=178) or atypical (n=82) patterns. Information on demographic factors, comorbid conditions, immunological markers, and microbiological data were gathered. Association was tested using chi-square tests, t-tests, and logistic regression to determine the independent predictors of atypical radiological presentation. Results: Atypical radiological presentation was noted in 31.5% of patients. This was significantly related to older age (?60 years, p<0.001), diabetes mellitus (p<0.001), chronic kidney disease (p=0.002), and malnutrition (p=0.011). Radiologically, atypical TB presented with lower- and middle-lobe involvement, mass-like opacities, pleural effusions, miliary patterns, and mediastinal lymphadenopathy (all p<0.001). Immunologically, patients with atypical TB presented with increased ESR (71.5 vs. 54.2 mm/hr, p<0.001), increased CRP (38 vs. 24 mg/L, p=0.002), and Microbiologically, sputum AFB smear was less positive in atypical TB (63.4% vs. 85.4%, p<0.001), while GeneXpert was uniformly positive in both groups. Multivariate analysis revealed age ?60 years (aOR 3.42), diabetes (aOR 2.67), CKD (aOR 2.48), and malnutrition (aOR 1.94) as independent predictors of atypical findings. Conclusion: Host-related factors, especially immunosuppression, comorbidities, and older age, significantly contribute to atypical radiological patterns of PTB. Knowledge of these relationships will prevent delays in diagnosis, particularly among high-risk patients. Interdisciplinary integration of radiological findings with clinical, immunological profiles, and molecular diagnostics can increase early diagnosis and treatment of atypical TB presentations.