A histological spectrum of host responses in tuberculous lymphadenitis.

A total of 446 lymph node biopsy specimens showing histological evidence of tuberculosis were classified into four groups based on the organization of the granuloma, the type and numbers of participating cells and the nature of necrosis. These were, hyperplastic (22.4%)--a well-formed epithelioid cell granuloma with very little necrosis, reactive (54.3%)--a well-formed granuloma consisting of epithelioid cells, macrophages, lymphocytes and plasma cells with fine, eosinophilic caseation necrosis, hyporeactive (17.7%)--a poorly organized granuloma with macrophages, immature epithelioid cells, lymphocytes and plasma cells and coarse, predominantly basophilic caseation necrosis and nonreactive (3.6%)--unorganized granuloma with macrophages, lymphocytes, plasma cells and polymorphs with non caseating necrosis. Though the number of bacilli in the sections differed in each group, there were no differences in culture positivity, Mantoux reaction or the clinical features. It is likely that the spectrum of histological responses seen in tuberculous lymphadenitis is the end result of different pathogenic mechanisms underlying the disease.