title: Reassessment of diagnostic criteria in cutaneous lymphocytic infiltrates.
abstract: BACKGROUND
  Non-specific lymphocytic infiltrates of the skin pose difficulties in daily practice in pathology. There is still a lack of pathognomonic signs for the differential diagnosis between benign and malignant lymphocytic infiltrates.
  
  
  OBJECTIVE
  To evaluate the morphological and immunohistochemical profile of lymphocytic infiltrations of the skin according to clinical outcome.
  
  
  METHODS
  Retrospective; histopathological and immunohistochemical analysis.
  
  
  METHODS
  Referral center, university hospital.
  
  
  METHODS
  28 cases of lymphocytic infiltrates of difficult differential diagnosis selected from the records.
  
  
  METHODS
  Eighteen histological variables and the immunophenotypic profile were assessed using the CD4, CD8, CD3, CD20 and CD30 lymphoid markers and compared to subsequent follow-up.
  
  
  RESULTS
  The most common diagnoses were: initial mycosis fungoides (eight cases) and drug reactions (five cases). Single morphological variables did not discriminate between benign and malignant infiltrates except for the presence of Pautrier-Darier's microabscesses, which were found only in mycosis fungoides (p = 0.015). Patterns of superficial and deep infiltration (p = 0.037) and also the presence of eosinophils (p = 0.0207) were more frequently found in benign lymphocytic infiltrates. Immunohistochemical profile of T-cell subsets showed overlap between benign and malignant infiltrates with a predominance of CD4-positive (helper) lymphocytes in the majority of cases.
  
  
  CONCLUSIONS
  A combination of clinical and histological features remains the most reliable approach for establishing a definite diagnosis in cases of lymphoid skin infiltrates.
authors.affiliation: Department of Pathology, School of Medical Sciences, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil.
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Cotta
authors.forename: Maria Letícia
authors.initials: ML
authors.lastname: Cintra
authors.forename: Elemir Macedo
authors.initials: EM
authors.lastname: de Souza
authors.forename: Luis Alberto
authors.initials: LA
authors.lastname: Magna
authors.forename: José
authors.initials: J
authors.lastname: Vassallo
mesh_terms: D015703:Antigens, CD / Q000032:analysis; D016516:CD4-CD8 Ratio; D016009:Chi-Square Distribution; D003937:Diagnosis, Differential; D005500:Follow-Up Studies; D006801:Humans; D009182:Mycosis Fungoides / Q000473:pathology*; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000473:pathology*; D018709:Statistics, Nonparametric
chemical_list: D015703:Antigens, CD