Demonstration of Chlamydia trachomatis in inguinal lymphadenitis of lymphogranuloma venereum: a light microscopy, electron microscopy and polymerase chain reaction study.

Intravacuolar organisms in vacuolated macrophages were associated with areas of necrosis and suppuration in 12 patients with suppurative inguinal lymphadenitis. The intravacuolar organisms measured 0.2 to 2.0 micrometers in diameter, stained Gram negative with the Brown-Hopp's tissue Gram stain, faintly blue with hematoxylin and eosin stain, and black with the Warthin-Starry silver impregnation stain. The organisms lined vacuolar membranes and/or clumped in centers of vacuoles. Electron microscopy revealed elementary and reticulate bodies and intermediate forms characteristic of the genus Chlamydia. Cultures of three lymph nodes in McCoy cells grew Chlamydia trachomatis, lymphogranuloma venereum (LGV) serovars. Polymerase chain reaction using primers for chlamydial 16S ribosomal DNA confirmed the organisms as Chlamydia in lymph nodes from nine patients. Recognition of chlamydial organisms by light microscopy in tissue sections of lymph nodes allows a definitive diagnosis of lymphogranuloma venereum.