PURPOSE: Previous reports have shown that in one third of cases transbronchial lung biopsy is non-diagnostic for sarcoidosis and carries a risk of pneumothorax and bleeding. Mediastinoscopy is often suggested as the next diagnostic step but entails significant cost and associated morbidity. EBUS-TBNA, however, is emerging as a safe, minimally invasive tool for the primary diagnosis of mediastinal and hilar lymphadenopathy. The purpose of this study was to document the diagnostic yield of EBUS-TBNA for pulmonary sarcoidosis.
METHODS: Consecutive patients referred to the Medical University of South Carolina bronchoscopy suite for suspected pulmonary sarcoidosis were included in the study. CXRs and CT scans were reviewed if available but were not mandatory. All patients underwent EBUS-TBNA of enlarged mediastinal or hilar lymph nodes. On-site cytology was used to assess adequacy of the samples (i.e. presence of lymphocytes). The presence of noncaseating granulomas without necrosis in the appropriate clinical setting was deemed adequate for the diagnosis of pulmonary sarcoidosis. A negative EBUS-TBNA result was defined as three adequate, negative samples. All patients underwent bronchoalveolar lavage, with AFB and fungal cultures sent on selected patients. Patients with negative EBUS-TBNA underwent transbronchial lung biopsy (TBLB) or endobronchial biopsy if tolerated along with clincal follow-up to determine the final diagnosis.
RESULTS: Seventeen patients were referred for evaluation. EBUS-TBNA demonstrated noncaseating granulomas without necrosis in 13 of 14 patients (93%) with the final diagnosis of sarcoidosis. The remaining 3 patients were true negatives following further clinical evaluation. Characteristic ultrasound features of pulmonary sarcoidosis included clustered, well-demarcated, iso-echoic nodes with increased vascularity. There were no complications. EBUS-TBNA, therefore, has a sensitivity of 93% and a specificty of 100% for the primary diagnosis of pulmonary sarcoidosis.
CONCLUSION: EBUS-TBNA is a safe, minimally invasive tool for the primary diagnosis of pulmonary sarcoidosis with a high degree of sensitivity and specificity.
CLINICAL IMPLICATIONS: EBUS-TBNA is an excellent alternative to TBLB and mediastinoscopy for patients with suspected pulmonary sarcoidosis.
DISCLOSURE: Susan Garwood, None.