Background and study aim: Sarcoidosis is a systemic disorder of unknown cause that is characterized by a pathological hallmark, noncaseating granuloma. Bilateral hilar lymphadenopathy (BHL) is a major clinical feature, but it is sometimes difficult to exclude other diseases, especially in cases where there are no pulmonary abnormalities (stage I). Bronchoscopic transbronchial biopsy is currently a popular method by which to obtain pathological material, but its diagnostic power is insignificant. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA), also attempted recently, makes the sampling of pathological material easier and better, but the diagnoses are still based on cytological findings. Our study aimed to evaluate the yield of transesophageal EUS-FNA for histological confirmation of stage I sarcoidosis.
Methods: The study was a prospective comparative study to investigate the diagnostic sensitivities of FNA cytology and FNA histology. Subjects were consecutive patients with BHL without lung lesions on chest radiographs or chest CT who were referred to our hospitals between December 2003 and April 2006. Transesophageal EUS-FNA was performed with 19-gauge needles instead of the conventional 22-gauge needles.
Results: Forty-one patients were included in this study, and both histological and cytological materials were obtained successfully by EUS-FNA in all patients. Histopathological examination of the FNA sample showed noncaseating granuloma in 34 (94.4%) of the 36 patients with a final diagnosis of sarcoidosis. In contrast, only 28 of the 36 (77.8%) were diagnosed as having sarcoidosis on the basis of cytological findings. The difference was statistically significant (P = 0.0444).
Conclusion: FNA histology is better suited than FNA cytology to establishing the diagnosis of stage I sarcoidosis, and EUS-FNA with a 19-gauge needle plays a important role in this process.