title: Evaluation of follicular T-helper cells in primary cutaneous CD4+ small/medium pleomorphic T-cell lymphoma and dermatitis.
abstract: BACKGROUND
  CD4+ small/medium-sized pleomorphic T-cell lymphoma (SMPTCL) is a controversial primary cutaneous lymphoma, in which the candidate neoplastic cells express a follicular T-helper phenotype. We describe 16 cases of SMPTCL and compare expression of PD-1, CXCL-13 and ICOS in these tumors with 40 dermatitis cases.
  
  
  METHODS
  Histopathologic examination and immunocytochemistry were performed for 16 tumors and 40 assorted dermatitis cases.
  
  
  RESULTS
  All but one patient presented with solitary lesions. Each biopsy revealed a dense nodular non-epitheliotropic infiltrate of atypical T-cells. Neoplastic cells were CD3+/CD4+/CD8(-)/CD30(-). Cutaneous recurrence occurred in one patient over a median follow up of 8 months (range 5-36). All tumors widely expressed PD-1 and ICOS to a lesser extent. CXCL-13 stained much fewer cells. Of the dermatitis cases, PD-1 (most numerous) and ICOS labeled lymphoid cells in all cases, albeit fewer than in the tumors, and CXCL-13 was negative in 32. A rosette pattern of PD-1 expression was identified in all the SMPTCL cases but not in dermatitis.
  
  
  CONCLUSIONS
  There remains uncertainty about the appropriate nosological status of SMPTCL, which some authors consider to be a pseudolymphoma. However, this study suggests a significant difference in the prevalence and pattern of follicular T-helper cell markers between this tumor and lymphoid proliferations known to be reactive.
authors.affiliation: St John's Institute of Dermatology, London, UK.
authors.forename: Mina S
authors.initials: MS
authors.lastname: Ally
authors.forename: Ranganna Y
authors.initials: RY
authors.lastname: Prasad Hunasehally
authors.forename: Manuel
authors.initials: M
authors.lastname: Rodriguez-Justo
authors.forename: Blanca
authors.initials: B
authors.lastname: Martin
authors.forename: Roberto
authors.initials: R
authors.lastname: Verdolini
authors.forename: Natalie
authors.initials: N
authors.lastname: Attard
authors.forename: Fiona
authors.initials: F
authors.lastname: Child
authors.forename: Ayoma
authors.initials: A
authors.lastname: Attygalle
authors.forename: Sean
authors.initials: S
authors.lastname: Whittaker
authors.forename: Stephen
authors.initials: S
authors.lastname: Morris
authors.forename: Alistair
authors.initials: A
authors.lastname: Robson
mesh_terms: D000328:Adult; D000368:Aged; D054382:Chemokine CXCL13 / Q000096:biosynthesis; D003872:Dermatitis / Q000378:metabolism / Q000473:pathology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D060889:Inducible T-Cell Co-Stimulator Protein / Q000096:biosynthesis; D016410:Lymphoma, T-Cell, Cutaneous / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D061026:Programmed Cell Death 1 Receptor / Q000096:biosynthesis; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology; D006377:T-Lymphocytes, Helper-Inducer / Q000378:metabolism / Q000473:pathology
chemical_list: C110663:CXCL13 protein, human; D054382:Chemokine CXCL13; C556692:ICOS protein, human; D060889:Inducible T-Cell Co-Stimulator Protein; D009363:Neoplasm Proteins; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor
keywords: PD-1; cutaneous lymphoma; follicular T-helper cell; pseudolymphoma; small/medium pleomorphic T-cell lymphoma