I am having a lump in my armpit and was diagnosed with tuberculosis via biopsy "histopathically " (as culture displayed no growth after 45 days ) .. now I am on treatment with Rcinex , ethambutol, pyrazinamide for 2.5 months ..Now another pulmonolgist advised me to have another biopsy for Gene Xpert test to know whether it is drug resistant or not.. but gene Xpert says no "MTB detected" so what does that mean ? can we say there is no Tb or is it something else ? however the size of lump has reduced after 2 month treatment ..it clinically feels better !