[Diagnosis of classic Hodgkin lymphoma and its imitators]

The diagnosis of classic Hodgkin lymphoma is made by detecting characteristic tumor cells in an equally characteristic and even dominant accompanying infiltrate. While the morphological subtype is not relevant to the treatment decision, it is all the more important to rule out "imitators" of Hodgkin lymphoma in the differential diagnosis. These are differential diagnoses that can only be recognized when the clinical context is taken into account and often only show subtle deviations in the immune profile of the neoplastic cells or the accompanying infiltrate. In younger patients, these differential diagnoses include primary infection with Epstein-Barr virus, immunodeficiency-associated lymphoproliferative disorders, and nodular lymphocyte-predominant Hodgkin lymphoma. In addition, in cases of mediastinal manifestation, a distinction must be made between primary mediastinal B‑cell lymphoma and gray zone lymphoma. In older patients, the most important "imitators" of classic Hodgkin lymphoma are T‑cell lymphomas and immunodeficiency-associated lymphoproliferative disorders.