2018 Update of WHO-EORTC Classification of Primary Cutaneous Lymphomas
As reported by Willemze and colleagues in Blood, the World Health Organization (WHO) and the European Organisation for Research and Treatment of Cancer (EORTC) have released a 2018 update of their classification of primary cutaneous lymphomas.
As noted by the authors, “Primary cutaneous lymphomas are a heterogeneous group of T-cell lymphomas and B-cell lymphomas that present in the skin with no evidence of extracutaneous disease at the time of diagnosis. In the last decade, the 2005 WHO-EORTC consensus classification has served as a golden standard for the diagnosis and classification of these conditions. In September 2018, an updated version of the WHO-EORTC was published in the 4th edition of the WHO classification for Skin Tumours Blue Book.”
Highlights of the update include the following:
- Primary cutaneous acral CD8+ T-cell lymphoma and Epstein Barr virus (EBV)-positive mucocutaneous ulcer are included as new provisional entities.
- A new section on cutaneous forms of chronic active EBV disease has been added.
- The term primary cutaneous CD4-positive small/medium T-cell lymphoma was modified to primary cutaneous CD4-positive small/medium T-cell lymphoproliferative disorder due to the indolent clinical behavior of the disease and uncertain malignant potential.
- Modifications have been made in the sections on lymphomatoid papulosis, increasing the spectrum of histologic and genetic types, and primary cutaneous marginal zone lymphomas, recognizing two different subtypes.
- The characteristic features of the new and modified entities and results of recent molecular studies with diagnostic, prognostic, and/or therapeutic significance for the different types of primary cutaneous lymphomas are reviewed.
- Updated information on the frequency and survival of the different types of primary cutaneous lymphomas is provided.
The authors noted, “[S]ince the publication of the first WHO-EORTC classification, much progress has been made and this 2018 update continues to be a useful guide for clinicians involved in the care for patients with a cutaneous lymphoma. Genome-wide genetic studies have contributed to a better understanding of the molecular pathways involved in the pathogenesis of the different types of cutaneous lymphomas and resulted in the recognition of additional diagnostic and prognostic criteria and new potential therapeutic targets. While genetic markers may become increasingly important, integration of histologic, immunophenotypic, genetic, and …clinical data remains essential for an accurate diagnosis. In the past decades, a multidisciplinary approach with collaboration between pathologists, dermatologists, hematologists, and radiation oncologists has been crucial for defining new entities and classifications, and is also the best guarantee for further progress in the diagnosis and treatment of patients with a cutaneous lymphoma.”
Rein Willemze, MD, of the Department of Dermatology, Leiden University Medical Center, is the corresponding author for the Blood article.
Disclosure: The study authors’ full disclosures can be found at bloodjournal.org.
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