Pathology of lymph node tuberculosis in Yaounde: diagnostic agreement based on the Kappa coefficient

Abstract

Introduction: lymph node tuberculosis remains widespread in Cameroon. Our goal was to compare the diagnostic agreement between the hematein-eosin coloration technique and the Ziehl-Neelsen technique.

Methods: this study is a retrospective and comparative study realized in the Yaounde University Teaching Hospital over a period of 5 years. We needed to specify the diagnostic agreement for tuberculosis, first inter observer and secondly between the standard and special colorations. The data we collected allowed us to determine the agreement rates observed and the kappa (k) coefficients with linear weighting.

Results: the 186 samples of the 1726 cases of tuberculosis of all locations represented a proportion of 10.78%. There were more male patients (65.05%) with a sex ratio (M:F) of 1.30. The average age was 24.21 ± 15.5 with the extremes from 5 to 68 years. The most represented age group was from 10 to 39 years. The two observers agreed in 93 cases using hematein eosin coloration (P₀ = 83.87 %; k = 0.8109) and on 73 samples using the Ziehl-Neelsen coloration (P₀ = 89.78 %; k = 0.7734). The two coloration techniques presented an agreement on 104 samples (P₀ = 88.17 %; k = 0.8783).

Conclusion: the routine choice of the hematein eosin coloration technique not paired with the coloration technique of Ziehl-Neelsen can effectively alleviate the program for fighting tuberculosis in an environment of limited resources.