title: Proliferative activity of epidermal and dermal T lymphocytes in mycosis fungoides.
abstract: BACKGROUND
  Mycosis fungoides (MF) is histologically characterized by an accumulation of T lymphocytes (T cells) in both epidermis and dermis. However, the mechanism of the formation of Pautrier's microabscess or the maintenance of the epidermal T cells has not yet been clarified.
  
  
  OBJECTIVE
  The rate of proliferation of these T cells was investigated.
  
  
  METHODS
  The formalin-fixed, paraffin-embedded sections from 9 cases of patch/plaque stage MF were immunostained with proliferating cell nuclear antigen (PCNA).
  
  
  RESULTS
  The PCNA-positive T cell nuclei were found both in the epidermis (including Pautrier's microabscesses) and dermis in all the specimens. The mean PCNA indices of the T cells were 20.2 +/- 10.6% (mean +/- SD) within the epidermis and 16.8 +/- 6.5% in the dermis, which was not statistically significantly different (p > 0.05). The ratio of the PCNA index between the epidermis and dermis was 1.3 +/- 0.6, which was not apparently correlated with the duration of the disease (8.4 +/- 5.1 years).
  
  
  CONCLUSIONS
  These findings suggested that in situ proliferation might contribute to the epidermal T cell population resulting in the formation of Pautrier's microabscesses and an increase in dermal T cell volume during the course of the disease.
authors.affiliation: Department of Dermatology, University of Ehime School of Medicine, Japan.
authors.forename: P
authors.initials: P
authors.lastname: Tu
authors.forename: S
authors.initials: S
authors.lastname: Miyauchi
authors.forename: Y
authors.initials: Y
authors.lastname: Miki
mesh_terms: D000038:Abscess / Q000473:pathology; D000328:Adult; D000368:Aged; D002455:Cell Division; D002467:Cell Nucleus / Q000648:ultrastructure; D004817:Epidermis / Q000473:pathology*; D005260:Female; D016193:G1 Phase; D006801:Humans; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D009182:Mycosis Fungoides / Q000473:pathology*; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D016196:S Phase; D012867:Skin / Q000473:pathology*; D012878:Skin Neoplasms / Q000473:pathology*; D013601:T-Lymphocytes / Q000473:pathology*
chemical_list: D018809:Proliferating Cell Nuclear Antigen