This study aims to evaluate the diagnostic yield and safety of different lung biopsy techniques in patients with interstitial lung diseases (ILD). The study compares transbronchial lung biopsy using forceps, transbronchial cryobiopsy, and thoracoscopic lung biopsy in terms of their ability to provide accurate diagnosis and associated complications. Interstitial lung diseases represent a heterogeneous group of diffuse parenchymal lung disorders that often require histopathological confirmation. This study will help determine the most effective and safest biopsy technique to improve diagnostic accuracy and patient outcomes.

Interstitial lung diseases (ILD) are a diverse group of diffuse parenchymal lung disorders characterized by inflammation and fibrosis. Accurate diagnosis is essential for appropriate management and prognosis. Lung biopsy is often required when clinical and radiological findings are inconclusive. Several biopsy techniques are available, including transbronchial lung biopsy using forceps, transbronchial cryobiopsy, and surgical thoracoscopic lung biopsy.

Transbronchial forceps biopsy is widely available but may have limited diagnostic yield due to small specimen size. Cryobiopsy provides larger tissue samples with better preservation of lung architecture, potentially improving diagnostic accuracy. Thoracoscopic lung biopsy is considered the gold standard but is more invasive and associated with higher risk.

This study aims to compare the diagnostic yield and safety profile of these biopsy techniques in patients with suspected interstitial lung diseases. The results of this study may help guide clinicians in selecting the most appropriate biopsy technique while minimizing complications.

Inclusion Criteria:

• age more than 18 years
• patients with no absolute contraindications for procedure
• cases who had clinical, laboratory and radiological criteria of ILD

Exclusion Criteria:

• patients with images typical of definite UIP and definite extrinsic allergic alveolitis
• clinical and radiological evidence of occupational lung diseases
• coagulation disorder, advanced uncompensated heart disease, uncompensated Type II Respiratory failure, severe grades of pulmonary hypertension
• pulmonary metastasis or lymphangitis carcinomatosis
• specific parenchymal pattern "honeycombing, probable UIP, diffuse end stage fibrosis, cystic lung diseases and advanced LAM and PLCH

Individual participant data will not be shared to protect patient confidentiality and privacy