Toxoplasma lymphadenitis. Analysis of cytologic and histopathologic criteria and correlation with serologic tests.

OBJECTIVE

To identify cases of Toxoplasma lymphadenitis by light microscopic examination of fine needle aspiration cytology (FNAC) smears and paraffin sections and to correlate the result with those of serologic tests.

STUDY

DESIGN

The study group consisted of 19 cases of Toxoplasma lymphadenitis, 7 of which were diagnosed by FNAC, 9 on excision biopsy and 3 on FNAC followed by biopsy. Nineteen cases of reactive lymphadenitis, tuberculosis and infectious mononucleosus composed the control group. Sera from all 38 patients were screened for antibodies to Toxoplasma.

RESULTS

Eleven of 19 cases (58%) of Toxoplasma adenitis had very high titers of antibody (> 300 ELISA units/ml), and 6 cases (31%) had antibody titers in a range suggestive of active infection (210-300 ELISA units/mL) and required demonstration of rising titers. Overall, 89% of patients with Toxoplasma lymphadenitis showed significant levels of antibody. All patients from the control group showed consistently low levels of antibody to Toxoplasma.

CONCLUSION

Though serologic tests are mandatory for the diagnosis of Toxoplasma lymphadenitis, a high index of suspicion can be obtained by means of light microscopy alone.