RT Journal Article SR Electronic T1 T-cell nature of leukaemic cells in a case of Sézary's syndrome with 'null-cell' features. JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP 912 OP 917 DO 10.1136/jcp.32.9.912 VO 32 IS 9 A1 Lauriola, L A1 Musiani, P A1 Carbone, A A1 Bartolini, M A1 Cianciulli, P A1 Piantelli, M YR 1979 UL http://jcp.bmj.com/content/32/9/912.abstract AB alpha-naphthyl acetate esterase (ANAE) activity has been investigated in leukaemic cells from peripheral blood in a typical small-cell Sézary syndrome (SS) case in which cerebriform mononuclear cells failed to form E rosettes. The 'dot-like' ANAE positivity found in the majority of these neoplastic cells strongly supports a T-cell origin. In addition, a non-monocytic, non-B-cell nature of Sézary cells is indicated by the lack of Ia-like antigens. Finally, there is evidence of a distinct portion of Sézary cells simultaneously expressing ANAE activity and Fc IgM receptors.