The role of tumour-infiltrating eosinophils, mast cells and macrophages in Classical and Nodular Lymphocyte Predominant Hodgkin Lymphoma in children

Objectives: To study Hodgkin lymphoma (HL) microenvironment in a Swedish paediatric population and its relation to clinical parameters. Methods: Tumour tissue from classical HL (cHL) (n = 87) and nodular lymphocyte predominant HL (NLPHL) (n = 11) was investigated for Epstein-Barr Virus (EBV) and analysed for eosinophils, mast cells and macrophages. Results: In cHL, EBV positivity was more common in low age (P < 0.001) and in mixed cellularity (MC) (P < 0.001). Higher mast cell infiltration was seen in stage III-IV (P < 0.001), and with presence of B-symptoms (P = 0.01). Cases with high mast cell counts displayed higher erythrocyte sedimentation rate (ESR), lower haemoglobin and albumin levels. Higher macrophage infiltration was seen in stage III-IV (P = 0.02) and there was elevated ESR and neutrophil count. All NLPHL cases were EBV negative, had lower rates of inflammatory cells and lower degree of inflammatory reaction in laboratory parameters. There was no difference in survival estimates with regard to infiltration of inflammatory cells. Conclusions: Higher levels of mast cells and macrophages in cHL tumours reflected the clinical presentation in laboratory parameters, B-symptoms and more advanced stages. NLPHL differs from cHL in numbers of inflammatory cells in the tumour, and in laboratory parameters.