Lymphoma lurks in lung shadows: Lung presentations in lymphoma

Background: Pulmonary involvement in lymphoma is uncommon and often mimics more prevalent respiratory diseases such as tuberculosis, pneumonia, or malignant pleural effusion, leading to delayed diagnosis. This study aimed to describe the clinical, radiological, and diagnostic characteristics of lymphoma patients presenting primarily with respiratory manifestations. Methods: We conducted a retrospective observational study of histologically confirmed lymphoma cases diagnosed in the Department of Pulmonary Medicine at a tertiary care center between 2023 and 2024. Clinical presentation, imaging findings, pleural fluid characteristics, diagnostic procedures, histopathological subtypes, and time to diagnosis were analyzed. Results: Ten patients (7 males, 3 females; mean age 47.7 years) were included. Breathlessness was the most common presenting symptom (50%), followed by fever (30%), chest pain (10%), and haemoptysis (10%). Four patients (40%) had been empirically treated with antitubercular therapy before diagnosis. Pleural effusion was the predominant radiological finding, occurring in 8 patients, with unilateral effusion in 62% of cases. Mean pleural fluid adenosine deaminase (ADA) level was 149.7 U/L; however, except for one outlier, all values were below 70 U/L. Radiological presentations included mediastinal masses, pulmonary consolidations, hilar masses, pleural thickening, and diffuse infiltrative lesions. Diagnostic confirmation was achieved through medical thoracoscopy ( n =3), transbronchial lung biopsy with endobronchial ultrasound-guided transbronchial needle aspiration ( n =1), lymph node excision biopsy ( n =1), endobronchial biopsy ( n =1), and CT/USG-guided biopsies ( n =4). Three patients had primary pulmonary lymphoma, while seven had secondary pulmonary involvement. The median time to diagnosis was 75 days. Conclusion: Lymphoma can present with diverse respiratory manifestations, frequently masquerading as tuberculosis or other pulmonary disorders. Persistent pleural effusions, non-resolving pulmonary consolidations, mediastinal masses, or atypical thoracic lesions should prompt consideration of lymphoma. Early tissue diagnosis, repeat biopsies when initial samples are inconclusive, and avoidance of prolonged empirical therapy are essential for timely diagnosis and management.