A 25-year-old woman presents with progressive shortness of breath and a dry cough. Chest imaging reveals bilateral hilar lymphadenopathy. Transbronchial lung biopsy demonstrates non-caseating granulomas. What is the most likely diagnosis?

- The presentation of bilateral hilar lymphadenopathy combined with non-caseating granulomas on transbronchial lung biopsy is characteristic of sarcoidosis.
- This systemic granulomatous disease commonly affects young adults, causing progressive dyspnea and dry cough.
- Unlike tuberculosis, sarcoidosis granulomas are non-caseating, and the absence of necrosis helps distinguish it from infectious causes.
- Hypersensitivity pneumonitis and Wegener’s granulomatosis have differing clinical and histological features, such as more prominent interstitial infiltration and necrotizing granulomas, respectively.
- Hence, the clinical and pathological findings strongly support the diagnosis of sarcoidosis.

Reference: Davidson’s Principles and Practice of Medicine, 23rd Edition, Chapter: Disorders of the respiratory system, Page 727.