Fine needle aspiration of toxoplasmic (Piringer-Kuchinka) lymphadenitis: a cytohistologic correlation study.
OBJECTIVE
To define the cytomorphologic features of toxoplasmic lymphadenitis (TL) and to establish the diagnostic sensitivity and specificity of the cytologic diagnosis.


METHODS
A cytohistologic correlation study of 11 patients in which a histologic diagnosis of TL was available. These cases were analyzed in a blind study among other cases of nonneoplastic lymphadenopathies. The results of the study are expressed in terms of diagnostic sensitivity and specificity. Although not included in the study, 3 other cases of TL with serologic confirmation were also reviewed.


RESULTS
Microgranulomas were a characteristic finding in TL. They consisted of small clusters of epithelioid histiocytes, each with abundant cytoplasm and an eccentric, oval nucleus. Diff-Quik-stained smears had cytoplasm with particularly pale staining and a homogeneous appearance. Most microgranulomas had a monotonous appearance with a few, small lymphocytes accompanying the epithelioid cells. No necrosis, suppurative changes or giant cells were present. Blind examination by 4 reviewers led to a correct diagnosis of TL in 9 of the 11 cases. Eight of the 9 cases were recognized by each of the 4 reviewers. One false positive diagnosis was made by 1 of the reviewers. The sensitivity of the diagnosis was 72.7-81.8% and the specificity 98.8-100%.


CONCLUSIONS
This study showed high sensitivity and specificity for the cytologic diagnosis of TL. Given the appropriate clinical context, the presence of characteristic epithelioid microgranulomas permits a diagnosis of TL. The cytologic diagnosis can be easily confirmed with serologic studies, thereby avoiding biopsy.
Viguer
José M
JM
Department of Pathology, University Hospital la Paz, Madrid, Spain.
Jiménez-Heffernan
José A
JA
López-Ferrer
Pilar
P
González-Peramato
Pilar
P
Vicandi
Blanca
B
D000293:Adolescent; D000328:Adult; D000818:Animals; D044963:Biopsy, Fine-Needle; D005189:False Positive Reactions; D005260:Female; D006099:Granuloma / Q000469:parasitology / Q000473:pathology; D006644:Histiocytes / Q000469:parasitology / Q000473:pathology; D006801:Humans; D008198:Lymph Nodes / Q000469:parasitology* / Q000473:pathology*; D008199:Lymphadenitis / Q000209:etiology / Q000469:parasitology* / Q000473:pathology*; D008214:Lymphocytes / Q000166:cytology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014122:Toxoplasma; D014123:Toxoplasmosis / Q000150:complications / Q000473:pathology*