Role of Bronchoscopic Techniques in the Diagnosis of Thoracic Sarcoidosis

Abstract

The diagnosis of sarcoidosis relies on clinical and radiological presentation, evidence of non-caseating granulomas in histopathology and exclusion of alternative causes of granulomatous inflammation. Currently, a proper diagnosis, with a high level of confidence, is considered as key to the appropriate diagnosis and management of the disease. In this sense, this review aims to provide a brief overview on the role of bronchoscopy in the diagnosis of thoracic sarcoidosis, incorporating newer techniques to establish, including endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), transesophageal ultrasound-guided needle aspiration with the use of an echo bronchoscope (EUS-B-FNA) and transbronchial lung cryobiopsy (TBLC). Most of the literature reports the diagnostic superiority of endosonographic techniques, such as EBUS-TBNA alone or in combination with EUS-FNA, over conventional bronchoscopic modalities in diagnosing Scadding stages I and II of the disease. Moreover, TBLC may be considered a useful and safe diagnostic tool for thoracic sarcoidosis, overcoming some limitations of transbronchial lung biopsy (TBLB), avoiding more invasive modalities and being complementary to endosonographic procedures such as EBUS-TBNA.

Keywords: diagnosis; recent bronchoscopic techniques; sarcoidosis; standard bronchoscopic techniques.

Figure 1

Endobronchial ultrasound in a patient with mediastinal lymph node abnormalities and suspicion of sarcoidosis diagnosis. EBUS-TBNA of an enlarged lymph node (station 4R) with homogeneous texture showed a non-necrotizing granuloma (hematoxylin-eosin and Giemsa).

Figure 2

Proposed diagnostic flowchart for bronchoscopic diagnosis of sarcoidosis. BALF: broncolaveolar lavage fluid; EBUS-TBNA: endobronchial ultrasound-guided transbronchial needle aspiration; EUS-FNA: endoscopic ultrasound-guided fine needle aspiration; EBB: endobronchial biopsy; TBLB: transbronchial lung biopsy; cTBNA: conventional transbronchial needle aspiration; TBLC: transbronchial lung cryobiopsy.