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Updated: Aug 8, 2026
Automated Multiplex Immunofluorescence Panel for Immuno-oncology Studies on Formalin-fixed Carcinoma Tissue Specimens
Published on: January 21, 2019
Immunohistochemical analysis of mycosis fungoides on paraffin-embedded tissue sections
1Department of Pathology, Loyola University Medical Center, Maywood, Illinois 60153, USA.
Insights
Immunophenotyping T-cell subpopulations in paraffin-embedded tissue using CD3, CD4, CD5, and CD8 monoclonal antibodies is effective for evaluating Mycosis Fungoides (MF) lesions. This method aids in confirming MF diagnosis and understanding T-cell phenotypes in skin biopsies.
Area of Science:
- Immunohistochemistry
- Dermatopathology
- Oncology
Background:
- Mycosis Fungoides (MF) diagnosis traditionally relies on flow cytometry or cryostat section immunohistochemistry.
- Paraffin-embedded tissues offer advantages for retrospective analysis and long-term storage.
- Advancements in monoclonal antibodies allow for T-cell subpopulation analysis in fixed tissues.
Purpose of the Study:
- To evaluate the utility of CD3, CD4, CD5, and CD8 monoclonal antibodies for immunophenotyping T-cell subpopulations in paraffin-embedded MF lesions.
- To assess the epidermal and dermal distribution of T and B cells in MF.
- To determine CD4:CD8 ratios in MF cutaneous lesions.
Main Methods:
- Retrospective review of 35 specimens (34 skin, 1 lymph node) from 29 MF patients.
- Immunophenotyping performed on paraffin sections using antibodies against CD3, CD4, CD5, CD8, and CD20.
- Analysis of T and B cell distribution and CD4:CD8 ratios.
Main Results:
- All cases showed a predominant CD3+ T-cell population.
- 32 cases exhibited a T-helper/inducer phenotype (CD3+, CD4+, CD5+).
- Aberrant CD5 expression was noted in three cases; altered CD4:CD8 ratios were observed in four cases.
- CD4+ T cells were the primary epidermotropic cells in 32 cases.
- CD20+ B cells were present in the dermal infiltrate of 17 cases.
Conclusions:
- Immunophenotypic analysis using CD3, CD4, CD5, and CD8 antibodies is valuable for histologic evaluation and confirmation of MF in paraffin-embedded tissues.
- This method can effectively characterize T-cell subpopulations in MF.
- The approach may be applicable to other neoplastic and non-neoplastic T-cell disorders in paraffin-embedded samples.
Abstract:
Mycosis fungoides (MF) is typically characterized by dermal and epidermal infiltration of T lymphocytes with a helper/inducer phenotype. Immunophenotypic analysis of such cases was traditionally performed by flow cytometry or immunohistochemistry on cryostat sections. With the advent of new monoclonal antibodies developed against T-cell antigens, including CD3, CD4, CD5, and CD8, it is now possible to immunophenotype T-cell subpopulations in paraffin-embedded tissues. To investigate the potential use of these antibodies for the evaluation of cutaneous lesions, 35 specimens (34 skin and 1 lymph node) from 29 patients with MF were retrospectively reviewed and immunophenotyped in paraffin sections with antibodies to CD3 (T-cell CD3), CD4 (NCL-CD4-1F6), CD5 (NCL-CD5-4C7), CD8 (CD8/144B), and CD20 (L26). Epidermal and dermal distribution of T and B cells were analyzed, and we assessed the ratios of CD4+ to CD8+ T cells. All of our 35 cases demonstrated a predominant CD3+ T-cell population. In 32 cases, the neoplastic cells expressed CD3, CD4, and CD5 consistent with a T-helper/inducer phenotype. In three cutaneous cases, the neoplastic CD4+ T cells showed minimal or absent expression of CD5, indicating an aberrant phenotype. In the majority of cases, minimal CD8+ T cells were present in the background, but in four cases, the CD4:CD8 ratios were 2:1 or less. Thirty-two cutaneous cases demonstrated epidermotropism exclusively by CD4+ T cells; one case showed both CD4+ and CD8+ T cells. In 17 cutaneous cases, scattered dermal CD20+ B cells were found individually or in small clusters within the background surrounding the neoplastic infiltrates. We concluded, therefore, that the immunophenotypic analysis of T-cell subpopulations using monoclonal antibodies of CD3, CD4, CD5, and CD8 was useful for histologic evaluation and confirmation of MF lesions in paraffin-embedded tissue. These antibodies might also provide an effective method of immunophenotyping other neoplastic and non-neoplastic T-cell populations in paraffin-embedded tissues.
