1. ¹Section of Dermatology, Department of Medical Sciences and Human Oncology, University of Turin, Turin, Italy
2. ²Department of Biomedical Sciences and Human Oncology, Section of Pathology, Center for Experimental Research and Medical Studies (CeRMS), University and ASO San Giovanni Battista, Turin, Italy

Correspondence: Professor Maria G Bernengo, Section of Dermatology, Department of Biomedical Sciences and Human Oncology, University of Turin v. Cherasco 23, 10126, Torino, Italy. E-mail: mariagrazia.bernengo@unito.it

Received 10 April 2007; Revised 20 July 2007; Accepted 13 August 2007; Published online 8 November 2007.

Abstract

Cutaneous T-cell lymphomas are a heterogeneous group of lymphomas where the tumor population emerges within a multiple subclone pattern ("clonal heterogeneity"). PCR analysis has been shown to be useful in the diagnosis of mycosis fungoides (MF) and Sézary Syndrome (SS). Focusing the attention on clonal heterogeneity, the efficacy of the multiplex/heteroduplex (HD) PCR and the GeneScan (GS) capillary electrophoresis analysis was compared in the early diagnosis of MF/SS, using a multiple sample approach. Indeed, GS demonstrated TCR gene rearrangement (GR) in all the 57 SS (100%) and in 123/146 (84%) of the MF samples, whereas the multiplex/HD PCR was less sensitive. An increase in clonality was observed in connection with both a worsening of the cutaneous disease (79% T1/T2; 100% T3/T4) and an increase in the histopathological score (HS<5, 76%; HS5, 94%). Clonal heterogeneity with adjunctive reproducible skin TCR-GRs was also observed. "Clonal instability," with different GRs, was present in a small percentage of patients. Therefore, it can be concluded that GS analysis in TCR-GR is able to improve diagnosis in MF/SS patients and the multiple sample approach is helpful for a correct interpretation of clonal patterns in skin lesions, especially in early-stage MF and in SS skin/blood samples.