Abstract: Primary cutaneous lymphoproliferative disorders are a group of heterogeneous diseases that mainly involve in skin and are completely different from lymph node lymphomas. Although rare, it is still an important part of lymphoid and hematopoietic tumors, and has many classification schemes. In the 2017 classification scheme of the World Health Organization and the 2018 updated version of WHO - EROTC classification, most entities did not change, but for some diseases, such as Epstein-Barr virus associated lymphoid tissue proliferative diseases and primary cutaneous CD4 positive small/medium T-cell lymphoma have modified, while new diseases have added. In this paper, the clinic and histologic features of these new and modified entities of primary cutaneous lymphomas are reviewed based on the the 2017 WHO and the 2018 WHO-EROTC classifications.

Key words: Lymphoproliferative disorders, Lymphoma, T-cell, cutaneous, Lymphoma, extranodal NK-T-cell, Lymphoma, B-cell