Hematopathological diagnosis of ”grey zone” lymphomas

Abstract

The World Health Organization (WHO) classification of hematopoietic neoplasms distinguish
individual histoclinical entities on the basis of integrated morphological, immunohistochemical, genetical
and clinical evaluation. Nevertheless, some of them can’t be precisely categorized although
significant progress in the experimental and clinical studies was made. Selected aggressive B-cell
lymphomas with clinical and biological overlapping between two different types of lymphomas are
incorporated into grey zone lymphomas. The diagnostic challenge has not only theoretical aspects
but crucially affects treatment options. In this article authors present criteria and diagnostic pitfalls
of two grey zone lymphomas in WHO classification: B-cell lymphoma, unclassifiable, with features
intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma and B-cell
lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma Burkitt
lymphoma. Moreover, diagnostic spectrum of lymphomas is discussed.