Primary Cutaneous Composite Lymphomas

Arch Pathol Lab Med. 2018 Nov;142(11):1352-1357. doi: 10.5858/arpa.2018-0283-RA.


Composite lymphomas have been defined as 2 distinct subtypes of lymphoma occurring at a single anatomic site. Composite lymphomas limited to the skin are a rare occurrence and pose a unique challenge. Many reported cases within the skin are combined B-cell and T-cell lymphomas, typically mycosis fungoides and a low-grade B-cell lymphoma. These cases are challenging to recognize because lymphoid infiltrates within the skin often include a mixed population of B cells and T cells. In particular, reactive lymphoid proliferations (pseudolymphomas), primary cutaneous low-grade B-cell lymphomas, and primary cutaneous CD4+ T-cell lymphoproliferative disorder may show nearly equal numbers of B cells and T cells. In order to exclude these possibilities, overwhelming evidence in support of each lymphoma is helpful, including abnormal architecture, cytology, and immunophenotype, as well as molecular genetic evidence of clonality.

Publication types

  • Review

MeSH terms

  • Composite Lymphoma / pathology*
  • Humans
  • Lymphoma, B-Cell / pathology*
  • Lymphoma, T-Cell / pathology*
  • Skin Neoplasms / pathology*