Immunodiagnosis in cutaneous T cell lymphoma: how does gene expression of the variable region of the T cell receptor fit into the diagnostic and pathophysiological picture of T cell neoplasia

M y c o s i s fiinge)idcs ( M F ) is a c u t a n e o u s ' I ' c-ell l y m p h o m a ( C ' l ' C l , ) w h i e h c a n p r e s e n t a s locali/.e-d i n ( l o l c n l pa l c lu s anel plac(uc-s l h a l c-linic-alK re-se-niblci n l l a n i m a t e i r y ekr i i i a loses , s u c h a s | ) s o r i a s i s , o r a s r a p i d l y preigrc-ssivc luiiie)rs w i t h i n l i l l r a l i o n of l y m p h nocle-s a n d \'isce-ra (1 ) . Flui m m u n o l o g } ' of C r F C F h a s in\cilve-cl nuillil'ae-c-le-d sludie-s e)l ' 'F e-cll r e g t i l a l i o n . In lliis c-chlorial rc-\ie-w, wel ocus on ihelalc-sl a|)|:)lie-alioii of n e w tc-chnolony elcsigiie-el lo cxple i i t t h e s c i e u l i r i c a d v a n c e s r e l a l c d lo iluonte)ocMi)' e)l I cc-ll c l o n a l c -xpans ion in l i i i m a n d i s e a s e |)roce-ssc-s. In acKance-d M F case-s, s i n \ i \ a l h a s t;c-iie-iall\" b e e n | ) oo r (2 , 3 ) , Howe-vc-r, somerc-ports ha\Ts i igg e s l e d a c u r a t i v e p o t e n t i a l (dc-fiiic-d a s bc-iiig d i s c a s e fn-e e i g h t y e a r s aftc-r t rea ln ie -n l is disc-onlimic-d) in e-arly (Stage1) M F w i l h lo|)ic-al ni l roge-n mi i s la re l a i u l / e i r leila! sk in e-leclrein-be-ain ihe-rapy ( 2 8 ) , O l h e r s l ia\ere-porle-d eeimbine-d l u o d a l i l y a p pre iac lu-s w i t h c-nc-ouragiug rcs i i l l s iu ihce-aiK sla.^e-s e)l M F, b u l n o sii ;nilic-aul i m p r e n c-mc-iils lii overall survixal ( , ' ) l l ) . Despite thefailure of these largeraiidomize-cl trials lo eurellunia |ori l \ ol palic-nts, llupote-utial for cure in some jialicnls with c-arly Ml' ' provides greal impc-lus for cslabl is lung this diagnosis as early in ils elcve-lopnu-iU as possible-. I Ie)we-\-ei, a palie-iil c-ousiderecl lo lia\-cM I ' c:liiiically may ree|iiiremany years and liumcreius biopsic-s be-lc)rellucliannoslichistology is ree-e)gnizc-d at llulight niie-ic)se-e)|)icIcve-l (12). Fluprinciple obstacle is the light microscopic asscssme-nt of early C'FC.L in thediirc-rc-ntialion hy the pathe)logist ot llulyniplie)pre)hlcrati\-e F cells of M F from benign, reactixe F cells associate'd with iullaiiimateiry skill disease-. In an c-HoiI lo ovc-rconullicsc liniilalie)ns in ree-ognizing early MF, several diHerent technique-s, i iul i iding T cell rece»pte)r ('FCK) gene rearraiigc-nu-nt studies and immunophenolyp i i ig of F cell markers , have been proposed as useful tools available lo helj) the diagnosis of M F ( IS . 14), M o Ic-culai-basc-d lc-clinic|iics ha\caltc-mptcd to disce-rn a elcinal popuial ion of 'F cells that was not a])parent on |-e-\icvv ol routine lu-nialoxylin/eosin-slainc-d sections.