AGNORS IN SKIN LESIONS OF CUTANEOUS MALIGNANT LYMPHOMAS AND PSEUDOLYMPHOMAS

Nucleolar organiser regions(NORs) are loops ofDNA situated on the short arms of acrocentricchromosomes 13,14,15,21,and 22.They can be dem-onstrated in formalin-fixed paraffin-embedded sec-tions by a one step silver technique;the resultant blackstructures are called AgNORs.The technique was usedin 71 patients with cutaneous malignant lymphomas(CML) and 9 cutaneous pseudolymphomas (CPL).AgNORs in 200 nuclei were scored and the means,standard deviation and standard error of the meanscalculated.Counts were as follows:mycosis fungoides(MF)Ⅰ(premycotic stage)1.17±0.09,SEM=0.01;MF Ⅱ (infiltrating stage)1.17±0.01,SEM=0.02;MF Ⅲ (tumor stage) 3.55±0.87,SEM=0.43:cutaneous peripheral T cell lymphomas other than MFand Sezary’s syndrome (SS) (CPTL) 2.55±1.11,SEM=0.35;SS 1.52;cutaneous B cell lymphomas(CBCL)2.18±0.18,SEM=0.06;CPL 1.17±0.1,SEM=0.03.There was a significant difference be-tween counts for CML (MF Ⅲ,CPTL,CBCL andSS) and CPL.Significant difference was also notedbetween scores for MF Ⅲ and CBCL,and especiallycounts between tumor stage (MF Ⅲ and CPTL) andpretumor stage (MFⅠand MF Ⅱ) of cutaneousperipheral T cell lymphomas.Although the AgNORtechnique is in the stage of research,it proves to behelpful in differentiating CML and CPL other thanseparating MFⅠand MF Ⅱ from CPL.