Diagnosis of mycosis fungoides: a comparative immunohistochemical study of T-cell markers using a novel anti-CD7 antibody.
Mycosis fungoides (MF) is the most common form of primary cutaneous T-cell lymphoma. In its early stage it may mimic benign dermatoses both on a clinical and histologic basis. MF usually expresses CD3 and CD4 (T-cell) markers. CD7 is expressed on about 90% of CD4 T cells and is often deficient on malignant T cells. Thus, CD7 may be useful in evaluating the nature of dermal lymphoid infiltrates. The aim of this study was to evaluate the usefulness of immunohistochemical detection of T-cell markers on paraffin-embedded sections, CD3 and CD7 (clone CBC.37), in the differential diagnosis of MF and benign dermatoses. Forty-two patients with diffuse dermal T-lymphocytic infiltrates were selected. Previous clinicopathologic correlation and follow-up had established the diagnosis of MF in 31 patients and benign dermatoses in 11. The mean value of stained cells in MF was 86.45% for CD3 and 53.09% for CD7 (P<0.001); in benign dermatoses it was 79.09% for CD3 and 73.63% for CD7 (P=0.669). CD7 immunolabeling was significantly lower in the MF group (P=0.048). A semiquantitative evaluation revealed a considerable loss of CD7 immunolabeling in comparison with CD3 in patients with MF. The authors conclude that CD7 study may represent a valuable tool in the distinction between inflammation and neoplasia in T-lymphoproliferative skin disorders.
Cotta
Ana Cristina
AC
Department of Pathology, Medical School of the State University of Campinas, Campinas, SP, Brazil.
Cintra
Maria Letícia
ML
de Souza
Elemir Macedo
EM
Chagas
Cristiano Aparecido
CA
Magna
Luis Alberto
LA
Fleury
Raul Negrão
RN
Brousset
Pierre
P
Vassallo
José
J
D019011:Antigens, CD7 / Q000097:blood*; D014408:Biomarkers, Tumor / Q000032:analysis*; D003937:Diagnosis, Differential; D006801:Humans; D007120:Immunochemistry; D009182:Mycosis Fungoides / Q000175:diagnosis* / Q000378:metabolism; D016612:Paraffin Embedding; D012871:Skin Diseases / Q000175:diagnosis / Q000378:metabolism; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D013601:T-Lymphocytes / Q000473:pathology
D019011:Antigens, CD7; D014408:Biomarkers, Tumor