Evidence based criteria for the histopathological diagnosis of toxoplasmic lymphadenopathy

Abstract

Aims: To formulate evidence based histopathological criteria for the diagnosis of acquired toxoplasmic lymphadenitis, in an area of high tuberculosis prevalence. Methods: Multiple histopathological parameters were assessed in a consecutive sample of biopsies from 68 patients presenting with lymphadenopathy with a duration of less than six months. Serum IgM enzyme linked immunosorbent assay was used as the standard reference test for the diagnosis of toxoplasmic lymphadenitis. The sensitivity, specificity, and likelihood ratios of various histological parameters were estimated. Results: The presence of microgranulomas (p , 0.0001), paracortical widening (p = 0.006), paracortical hyperplasia (p = 0.02), monocytoid B cells in sinuses (p = 0.007), lower than grade 2 macrogranuloma (p = 0.002), and the absence of giant cells (p = 0.05) were found to discriminate between IgM positive cases and IgM negative controls. Using a composite criterion-(1) presence of microgranulomas, (2) lower than grade 2 macrogranuloma, (3) absence of giant cells, and (4) follicular hyperplasia-toxoplasmic lymphadenitis can be diagnosed with a high degree of sensitivity (100%), specificity (96.6%), and positive likelihood ratio (29). Conclusion: Toxoplasma lymphadenitis can be diagnosed with a high degree of confidence using the specific histopathological criteria identified here.

Diagnosis of Toxoplasmic Lymphadenopathy: Comparison of serology and histology

“…10,11 In this study group, positive antibody carriage of only 35.3 % was observed among patients histologically diagnosed as having Toxoplasma lymphadenopathy, indicating low reliability of histology in the diagnosis of toxoplasmic lymphadenopathy. Findings are comparable to a study done by Eapen et al, 12 while some other studies have reported even lower figures of 22.5 %. 13 Diagnosis of toxoplasmosis can be done by a number of methods, either directly by PCR, hybridization, histology and isolation or via serological methods.…”

Misdiagnosing Whipple's disease in the young

“…The biopsy demonstrated small microgranulomata without associated necrosis closely associated with lymphoid follicles, findings which are consistent with evidence-based criteria for the histological diagnosis of toxoplasmosis 4. The histological examination was verified by three experienced histopathologists and the patient initially responded to treatment targeted at toxoplasmosis.…”

The Differential Agglutination Test as a Diagnostic Aid in Cases of Toxoplasmic Lymphadenitis

“…The presence of these histological abnormalities alone, when typical, can suffice for the diagnosis. However, to increase the diagnostic yield, serological testing is recommended both in patients with the classical histological features and in those patients with atypical histological findings (6,8). It is noteworthy that fine needle aspiration is rarely useful for the diagnosis, since it allows visualization of only a few isolated cells and does not permit the evaluation of lymph node architecture necessary to detect the classical histological features observed for TL (6,8).…”