[Diagnostic challenges in Kimura's disease].

Unlabelled: Ultra-rare diseases occur with a frequency of 2 in 100 000 people or less. Kimura's disease (KD) affects less than 1 in 1 000 000 people. It is a benign, chronic inflammatory soft tissue disorder, accompanied by eosinophilia, raised immunoglobulin E (IgE) titer and the presence of painless subcutaneous masses, usually in the head and neck region. The disease was first described in 1948 and occurs at higher rates in Asia than in America or Europe.

A Case Report: A 35-year-old man without past medical history presented to his family doctor for bilateral cervical lymphadenopathy accompanied by eosinophilia. Despite subsequent in-depth diagnostics, including fine-needle aspiration biopsy (FNAB) of the lymph nodes, the definitive diagnosis was not initially established. After following 2 months, a selective lymphadenectomy was performed, putting Hodgkin's lymphoma under suspicion. The image of positron emission tomography coupled with computed tomography (PET-CT) corresponded to this diagnosis. Due to the lack of all the criteria necessary to make a diagnosis, another histopathological consultation was done. The image of the lymph nodes suggested reaction-inflammatory changes. Due to the presence of a triad of signs (reactive lymphadenopathy, several eosinophils in the paracortic zone, vascular proliferation), differential diagnosis was recommended, among others towards the Kimura's disease. A series of examinations allowed to exclude lymphadenopathy of parasitic, allergic and hyperplastic hematopoietic system aetiology. The patient started steroid therapy with a good effect at first. However, after the recurrence of the disease, the patient was qualified to intensify the immunosuppressive treatment.

Conclusions: In the described case, the intensive diagnostic process and the thorough analysis of the test results relatively quickly led to the correct diagnosis. This enabled the implementation of appropriate treatment and prevented the initiation of empirical therapy for the originally diagnosed Hodgkin's lymphoma.