title: Mycosis fungoides with a CD56+ immunophenotype.
abstract: We report 3 cases of mycosis fungoides (MF) with a CD56+ cytotoxic immunophenotype. Each patient presented with a different clinical phenotype: one exhibited limited poikilodermatous patches (skin stage T1); one, widespread hypopigmented lesions (skin stage T2); and one, poikiloderma with a single cutaneous tumor (skin stage T3). MF was confirmed both histologically and by the presence of a T-cell receptor clone in lesional skin in all cases. CD56 and T-cell intracellular antigen-1 were expressed by the malignant lymphocytes in all patients and two expressed CD8. No sample demonstrated loss of the pan T-cell markers CD2 or CD3. None of the 3 developed systemic disease and T-cell receptor gene analysis of peripheral blood was polyclonal in all cases. Only 3 cases of CD56+ MF have been reported previously, none of which exhibited tumor-stage disease. Currently, the disease in our patients appears to be behaving in a manner similar to that predicted for MF with a normal immunophenotype but the prognosis has to be guarded in view of the rarity of this subtype.
authors.affiliation: Skin Tumor Unit, St John's Institute of Dermatology, St Thomas' Hospital, London, UK. marywain@doctors.net.uk
authors.forename: E Mary
authors.initials: EM
authors.lastname: Wain
authors.forename: Guy E
authors.initials: GE
authors.lastname: Orchard
authors.forename: Susan
authors.initials: S
authors.lastname: Mayou
authors.forename: David J
authors.initials: DJ
authors.lastname: Atherton
authors.forename: Klaus J
authors.initials: KJ
authors.lastname: Misch
authors.forename: Robin
authors.initials: R
authors.lastname: Russell-Jones
mesh_terms: D000328:Adult; D019002:CD56 Antigen; D002648:Child; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D009182:Mycosis Fungoides / Q000276:immunology*; D012878:Skin Neoplasms / Q000276:immunology*
chemical_list: D019002:CD56 Antigen