Clinical-histologic-microbiologic analysis of 419 lymph node biopsy specimens.

The results of culture and histopathologic examination of 419 lymph node biopsy specimens obtained from 414 patients in 1978-1983 were correlated with clinical histories. The clinical diagnosis was lymphadenopathy of unknown etiology in 113 cases, sarcoidosis in 93, malignant lymphoma in 86, metastatic carcinoma in 17, histoplasmosis in 18, tuberculosis in 13, and other miscellaneous conditions in 79. All but two clinically significant microbial isolates from lymph nodes were either mycobacteria or fungi: the only exceptions were staphylococcal isolates from two children with lymphadenitis. Of 66 lymph nodes associated with bacterial, mycobacterial, or fungal disease, 48 included granulomatous and/or acute inflammatory lesions. Of 33 lymph nodes that were culture-positive, two had histologic evidence of lymphoid hyperplasia, and the remainder included granulomatous and/or acute inflammatory lesions. With one exception, lymph node cultures in immunocompetent patients were positive only when there was a granuloma and/or an acute inflammatory lesion in the tissue. On the basis of these findings, it was concluded that lymph nodes from immunocompetent patients should be cultured only when a granuloma and/or an acute inflammatory lesion are detected and that the cultures can be limited to mycobacteria and fungi.