Tuberculosis is the world's foremost cause of death from a single infectious agent in adults. During the past decade the nature and magnitude of the problem of tuberculosis have dramatically changed. Much of what physicians have learned about this disease is no longer true and tuberculosis has become a new entity. Migration from developing areas with a high prevalence of tuberculosis to industrialized countries, and the problem of HIV infection, have introduced new components to the epidemiology. We report three cases of young immigrants with lymph node tuberculosis. One patient was successfully treated with the usual 9-month-regimen. The other 2 patients, however, developed new lymph nodes or enlargement of existing nodes during treatment. They underwent further examinations, including surgical biopsies, because of diagnostic uncertainty (tuberculosis, superinfection or lymphoma). Finally the 2 patients were successfully treated with antituberculous agents for 12 and 15 months. These cases prompted a review of the literature and a reevaluation of the management of lymph node tuberculosis, including the value of surgical biopsy in the diagnosis of tuberculous lymphadenitis. We conclude that selective surgical biopsies should be recommended for differential diagnosis of tuberculous lymphadenitis. Histological examination (caseating epitheloid cell granulomas and giant cell formation) and microbiological examination (Ziehl-Neelsen staining and culture of native material) should be performed. Newer methods, such as amplification and detection of mycobacterial DNA, are rapid and sensitive tests helpful for diagnosis. Lymph nodes may increase in size and new nodes may appear both during and after chemotherapy, without indicating a failure of treatment or relapse. The usual treatment is a 9-month-regimen with rifamipicin, isoniazid, pyrazinamid and ethambutol. Prolonged or modified regimens are, however, necessary in some individuals.