Objective: To evaluate the role of videomediastinoscopy combined with the examination of CD(4)/CD(8) in the diagnosis of tuberculosis and sarcoidosis of the mediastinum.
Methods: The clinical records of 90 patients who underwent videomediastinoscopy from February 2003 to September 2005 were retrospectively reviewed. The expression of CD(4)/CD(8) was studied using immunohistochemical method in the tissues from 57 cases with a diagnosis of tuberculosis or sarcoidosis and noncaseating granuloma without classical "sarcoid" pathology obtained by videomediastinoscopy.
Results: Sarcoidosis was diagnosed in 37 patients, tuberculosis in 14 patients, lymphoma in 15 patients, nodal metastasis in 18 patients, noncaseating granuloma without classical "sarcoid" in 6 patients. The diagnostic accuracy was 93.3% (84/90). The expression of CD(4) and CD(8) in sarcoidosis was (65 +/- 13)% and (9.4 +/- 2.6)%, respectively. While the expression of CD(4) and CD(8) in tuberculosis was (41 +/- 11)% and (11.8 +/- 3.4)%, respectively. The rate of CD(4)/CD(8) in sarcoidosis was higher than that in tuberculosis (7.3 +/- 1.8 and 3.6 +/- 1.1, respectively, t = 1.883, P = 0.000). The accuracy, specificity and sensitivity for diagnosis of sarcoidosis was 90.2%, 85.7% and 91.9%, respectively, if the cutoff value of CD(4)/CD(8) was 5. No complication or mortality was reported.
Conclusion: Videomediastinoscopy is an effective procedure for the diagnosis of mediastinal diseases. The examination of CD(4)/CD(8) adds more information to the differentiation of tuberculosis from sarcoidosis.