Chronic Lymphadenopathy Due to Mycobacterial Infection. Clinical Features, Diagnosis, Histopathology, and Management

This report provides clinical information, diagnostic criteria, management, and outcome of 153 cases of mycobacterial lymphadenitis; 22 patients (14%) had Mycobacterium tuberculosis (TB) and 131 patients (86%) had nontuberculous mycobacterial (NTM) disease. Correct diagnosis of TB v NTM disease is essential, since antituberculous chemotherapy was effective for TB adenitis, while excisional biopsy was the treatment of choice for NTM adenopathy. Dual (PPD-NTM, PPD-T) Mantoux tests discriminated between TB and NTM adenitis in 151 (99%) of 153 patients, while dual (PPD-Battey [B], PPD-T) tests differentiated between NTM and TB adenitis in 135 (88%) of 153 cases. A PPD-T reaction of 1 to 14 mm suggested either an NTM or TB infection, whereas a PPD-T of 15 mm or greater was strongly associated with TB disease. We recommend the use of PPD-B and PPD-T antigens as reliable diagnostic discriminators between TB and NTM adenitis.