Pulmonary Tuberculosis Involving the Right Middle Lobe of the Lung: CT and Clinical Characteristics

Abstract

Purpose: To describe the CT and clinical features of tuberculosis involving the right middle lobe of the lung. Materials and Methods: Among patients diagnosed with pulmonary tuberculosis at our hospital during the past three years, 16 cases (mean age of patients: 72 years) were reviewed for radiological and clinical presentation of patients that underwent CT and chest radiography and showed mainly right middle lobe involvement. Results: Middle lobe collapse or consolidation (n=16) and bronchial stenosis or obstruction without the presence of soft tissue masses (n=15) were the main findings. Enlarged mediastinal or hilar lymph nodes (n=15), cavities within consolidated tissue (n=2), ill-defined centrilobular nodules (n=12), a tree-in-bud appearance (n=10), focal consolidations (n=7) and small nodules (n=4) were found. All patients were older than 64 years and most complained of non-specific symptoms. A sputum smear for AFB was positive in four cases. Conclusion: A diagnosis of tuberculosis in the right middle lobe is suggested in older patients with following CT findings: 1) middle lobe collapse or consolidation; 2) middle lobe bronchus stenosis or obstruction without the presence of soft tissue masses; 3) mediastinal or hilar lymphadenopathy; 4) cavities within consolidation, and centrilobular nodules with branching linear structure in the adjacent lungs. Further evaluation such as bronchoscopy is recommended for confirmation even when the sputum smear for AFB is negative.