Minimally invasive diagnosis of sarcoidosis by EBUS when conventional diagnostics fail

Endobronchial ultrasound-guided transbronchial fine-needle aspiration (EBUS) is a minimally invasive method used routinely for mediastinal staging of patients with lung cancer. EBUS has also proved to be a valuable diagnostic tool for patients with different intrathoracic lesions who remain undiagnosed despite bronchoscopy and CT-guided fine-needle aspiration.

The present study focused on EBUS for diagnosing sarcoidosis.

During a 3-year period 308 of 601 patients who underwent EBUS at our institution were referred for further diagnostic of a radiologically suspicious lesion in the lung parenchyma (n = 195), enlarged lymph nodes in the mediastinum (n = 89), a suspicious tumor in the mediastinum or pleural disease (n = 24) but no one had a definite histological diagnosis. All charts were reviewed retrospectively.

Of the 308 patients 43 (14%) were eventually diagnosed with sarcoidosis. Thirty-three (77%) were diagnosed with EBUS. In the remaining 10 patients EBUS did not provide adequate tissue samples in 4 (9%) and in 6 patients (14%) EBUS provided adequate tissue but no definite diagnosis. EBUS was significantly better to establish the diagnosis in patients with enlarged mediastinal lymph nodes compared with isolated lung parenchymal involvement (85% vs 63%, p < 0.05).

EBUS is a valuable minimally invasive diagnostic modality to establish the diagnosis of sarcoidosis of unselected patients with undiagnosed intrathoracic lesions after conventional work up--particularly if patients have enlarged mediastinal lymph nodes. This minimally invasive procedure provides a final diagnosis without exposing the patient to the risk of complications from more invasive procedures.