Transbronchial lung biopsy (TBLB) is a bronchoscopic procedure used to obtain peripheral lung tissue. Small size and artefacts cause variable, and usually poor, diagnostic yield. The use of cryoprobes may allow for larger size and better quality biopsy samples.

Objectives:To analyze the histological quality and immunohistochemical findings of samples obtained by cryoprobe compared with TBLB obtained by conventional forceps and to assess the safety and complications of TBLB with cryoprobe versus the conventional method.

Methodology:

Prospective randomized study of 80 patients. The transbronchial lung biopsy was indicated for diagnoses of a interstitial lung disease. In both procedures the videobroncoscopy used will be a Olympus 260-T.

The transbronchial lung biopsy will be carried out with conventional forceps (Boston ® Biopsy Forceps, Ref 1556 and Olympus ® FB-19E) and cryoprobe (Erbokryo AC ®). TBLB will be performed by fluoroscopy guided and the cryoprobe or forceps will place in an area of the peripheral lung previously selected according to CT findings. Lung biopsies will be processed: The samples submitted for histological analysis will be fixed in formalin and embedded in paraffin. Staining will perform with hematoxylin-eosin and Masson's trichrome and the samples will be analyzed by a pathologist according to a protocol. The samples submitted to immunohistochemical study will be frozen (liquid nitrogen) for later transport.The specifical monoclonal antibodies will be used for immunohistochemical analysis.

Inclusion Criteria:

• Patients with Interstitial Lung disease.

Exclusion Criteria:

• Respiratory failure,haemodynamic instability, haemoptysis.