B42-20 A Comparison of the Clinical Characteristics of Mediastinal Lymph Node Tuberculosis and Mediastinal Lymph Node Sarcoidosis From a Tuberculosis Endemic Setting

Abstract Rationale Large patient cohort studies comparing the clinical characteristics of Mediastinal Tuberculosis and Sarcoidosis are lacking. Differentiating TB and Sarcoidosis is challenging especially in Tuberculosis endemic settings, leading to frequent misdiagnoses and incorrect treatment. Methods This was a prospective and retrospective cohort data analysis of patients diagnosed with granulomatous mediastinal adenopathy, including sarcoidosis and tuberculosis, and was conducted between August 2023 to August 2025 in New Delhi, India. We included patients with predominant isolated mediastinal lymphadenopathy due to the two disease entities. Results The study included 197 patients with Mediastinal lymph node TB and 256 with Scadding Stage 1 Sarcoidosis. Patients with pulmonary sarcoidosis were older (40.4 vs. 35.5 years, p < 0.001), had a higher BMI (26.2 vs. 22.7, p < 0.001), significantly more comorbidities [diabetes, hypothyroidism and hypertension], and a greater duration of symptoms (median 120 vs. 60 days, p < 0.001). Cough, breathlessness, joint pains and skin involvement were more common in sarcoidosis while weight loss (50.3% vs. 32.0%, p < 0.001), loss of appetite, and fever were more common in TB (44.7% vs. 30.9%, p = 0.003). Elevated Serum ACE levels (median 58 vs. 35.6 IU/L, p < 0.001), hypercalciuria, hypercalcemia, and tuberculin anergy (70.7% vs. 10.6%, p < 0.001) were more frequent in Sarcoidosis. Normal chest radiographs were more common with TB (33% vs 0%, p < 0.001), with more subjects having single lymph node station involvement (21.8% vs. 1.9%, p < 0.001), necrotic lymph nodes (64.9% vs. 8.2%, p < 0.001), and pleural effusion (6.6% vs. 2.0%, p = 0.012) on CT scan. Subjects with Sarcoidosis demonstrated greater multi-station lymph node involvement (91.4% vs. 52.3%, p < 0.001), and more patients having parenchymal involvement on CT scan. On EBUS, lymph nodes in tuberculosis more frequently demonstrated heterogeneous echotexture (57.4% vs. 2.2%, p < 0.001) and coagulation necrosis sign (38.1% vs. 1.7%, p < 0.001). On histopathological findings, necrotizing granulomas were more common in tuberculosis (28.7% vs. 6.1%, p < 0.001), while non-necrotizing granulomas were more common in sarcoidosis (71.5% vs. 36.5%, p < 0.001). Conclusion Sarcoidosis and Mediastinal TB have multiple differences in the clinical, radiological and histopathological parameters. A comprehensive assessment can allow a confident differentiation between the two disease entities. This abstract is funded by: None