Study objectives: The ability to diagnose sarcoidosis
cytologically has been reported previously, but the method is rarely
used. Endoscopic ultrasonography (EUS) is a sensitive technique for
detecting mediastinal lymph nodes, which in addition provides an
opportunity to carry out guided fine-needle aspiration (FNA) cytology.
We report herein on the use of EUS-FNA in the diagnosis of
Patients and methods: Nineteen patients
with suspected sarcoidosis were investigated using EUS-FNA with a
linear echoendoscope and a 22-gauge Hancke-Vilman needle.
Measurements and results: In all 19 patients, EUS revealed
enlarged mediastinal lymph nodes (mean size, 2.4 cm), located
subcarinally (n = 15), in the aortopulmonary window (n = 12), or in
the lower posterior mediastinum (n = 5). The nodes had an isoechoic
or hypoechoic appearance, with atypical vessels in five cases. The
amount of aspirate obtained using EUS-FNA was adequate in all patients,
and contained blood in excess of normal in some, indicating a high
degree of vascularity. Cytology demonstrated epithelioid cell granuloma
formation, suggesting sarcoidosis. Mycobacterial cultures were negative
in all of the patients except one, in whom the final diagnosis was
tuberculosis. The specificity and sensitivity of EUS-FNA in the
diagnosis of sarcoidosis were 94% and 100%, respectively.
Conclusions: EUS of mediastinal lymph nodes in sarcoidosis
reveals certain characteristic features. However, it is not capable of
differentiating the lesions from tuberculosis or malignancy. EUS-FNA is
a safe and sensitive method of aspirating material for cytology and
mycobacterial cultures. We believe it will provide a useful alternative
in the diagnosis of sarcoidosis.