Primary Cutaneous CD4+ Small/Medium T-Cell Lymphoproliferative Disorders: A Clinical, Pathologic, and Molecular Study of 60 Cases Presenting With a Single Lesion: A Multicenter Study of the French Cutaneous Lymphoma Study Group

Am J Surg Pathol. 2020 Jul;44(7):862-872. doi: 10.1097/PAS.0000000000001470.

Abstract

Primary cutaneous CD4 small/medium T-cell lymphoproliferative disorder (PCSMLPD) is a recently recognized entity in the 2017 World Health Organization (WHO) classification. It belongs to the T-follicular helper (TFH) lymphoproliferations. The clinical, pathologic, and molecular features of this localized disease are underresearched. We conducted a retrospective multicentric study of 60 patients with a PCSMLPD that presented as a single cutaneous lesion. Clinical, pathologic, and targeted molecular analyses were performed. PCSMLPD presented mostly as a nodule (45%), located on the head and neck area (50%) in adults (mean age: 59 y [43.3 to 75.2]). All patients had an indolent disease course, either at initial staging or during follow-up (mean: 16.6 mo [1.3 to 31.9]). Spontaneous regression was reported in 31.9% of cases. The infiltrates were most often nodular and/or diffuse, expanding in the whole dermis (78%, Pattern 1), rather than subepidermal band-like in the superficial dermis (22%, Pattern 2). Epidermotropism, folliculotropism, and capillary hyperplasia were common. The expression of TFH lineage markers was more extensive in lesions with Pattern 2, but a substantial B-cell infiltrate was seen in both types of lesions. A clonal rearrangement of the TCR genes was identified in 68% of cases. One sample of the 13 tested revealed a mutation in the DNMT3A gene among the 9 genes studied (TET2, DNMT3A, IDH2, RHOA, SETD2, PLCG1, STAT3, STAT5B, and CD28). PCSMLPD follows a benign clinical course and can spontaneously regress after biopsy. Although PCSMLPD expresses TFH lineage markers, mutations usually found in angioimmunoblastic T-cell lymphomas are uncommon.

Publication types

  • Multicenter Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / metabolism
  • CD4-Positive T-Lymphocytes / metabolism
  • Female
  • Follow-Up Studies
  • France
  • Humans
  • Immunohistochemistry
  • Lymphoma, T-Cell, Cutaneous / diagnosis*
  • Lymphoma, T-Cell, Cutaneous / genetics
  • Lymphoma, T-Cell, Cutaneous / metabolism
  • Lymphoma, T-Cell, Cutaneous / pathology
  • Male
  • Middle Aged
  • Mutation
  • Phenotype
  • Remission, Spontaneous
  • Retrospective Studies
  • Sequence Analysis, DNA
  • Skin Neoplasms / diagnosis*
  • Skin Neoplasms / genetics
  • Skin Neoplasms / metabolism
  • Skin Neoplasms / pathology

Substances

  • Biomarkers, Tumor