T cell receptor gene rearrangement analysis in mycosis fungoides and disseminated lymphocytoma cutis.

A cDNA from the CT beta 2 region of the T cell receptor gene was used as a probe to investigate the clonal composition of T cells in the skin lesions of 3 patients with mycosis fungoides (MF) and 1 patient with disseminated lymphocytoma cutis (DLC). All of these skin lesions showed helper/inducer T cell dominant infiltration. Clonal T cell populations, as evidenced by rearranged DNA bands, were demonstrated in all the skin lesions of the 3 patients with MF, but not in the lesion of the patient with DLC. The patients with MF appeared to have the same gene rearrangement pattern in DNA obtained from separate lesions, providing evidence that the T cells in both sites were derived from the same clone. Our results show that this gene rearrangement analysis helps to diagnose difficult cases of lymphoproliferative disorders.