Uncommon lymphadenopathies of immunopathogenesis can be misinterpreted as malignant diseases.

Lymphadenomegaly is a common sign of benign and malignant disorders. In our practice, only every fifth patient is found to have primary or secondary nodal malignancy. Benign disorders, including banal infections and other non-neoplastic conditions, however, cause most of the cases. Among these, there are some rare entities, resulting in persistent lymphadenopathy that may cause differential diagnostic problems in the daily practice. We report here three patients, having Rosai-Dorfman disease, multicentric Castleman's disease and Kikuchi's lymphadenitis, who exemplify such cases. Our purpose with this presentation is to emphasise importance of vigorous co-operation between clinicians and pathologists. In general, it is imperative to prefer specialised haematopathological laboratories that may facilitate proper diagnosis.