Mycobacterial cervical lymphadenitis: the histological features of non-tuberculous mycobacterial infection

Aims: The distinction between nontuberculous mycobacterial (NTM) lymphadenitis and other causes of cervical lymphadenitis is critical, as different entities call for different treatments. Despite modern diagnostic techniques for NTM infections their prompt and accurate diagnosis is still difficult. We assessed the value of different histological features in diagnosing clinically suggestive NTM cervical lymphadenitis in cases of granulomatous cervical lymphadenitis. Methods and results: A retrospective study of 30 patients with a clinical diagnosis of NTM cervical lymphadenitis was carried out. The patients were divided into three subgroups and several histological parameters were examined in each subgroup. A comparison was made with cases of proven tuberculous lymphadenitis. Four histological features (presence of microabscesses, ill-defined granulomas, noncaseating granulomas and a small number of giant cells) were found with significant statistical difference when comparison was made between the NTM group and the tuberculosis group. Conclusions: A rapid and accurate diagnostic procedure for NTM lymphadenitis is not yet available. Therefore, in the presence of a suggestive clinical picture for NTM lymphadenitis, we propose four histological features which support this diagnosis, thus allowing prompt therapeutic intervention.