Diagnosis and treatment of skin T-cell lymphoma undergoing transformation in lymphosarcoma

Aim. To define complex of parameters characterizing transformation of skin T-cell tumors in lymphosarcoma; to show specific treatment of patients with this transformation.
Material and methods. Of 57 patients with primary T-cell lymphomas of the skin (mycosis fungoides, Sezary's disease), we studied 12 patients with transformation of the process into lymphosarcoma by clinical, histological, moleculobiological and immunophenotypical parameters.
Results. We found that transformation of T-cell lymphoma into lymphosarcoma occurred in different time from the disease onset (2-12 years). In patients with mycosis fungoides (MF) the transformation was local while in those with Sezary's disease (SD) transformation of the tumor clone was determined by appearance of peripheral blood tumor cells rejuvenation. Morphological alterations were accompanied with immunomorphological parameters of progression. Most significant of them were high expression of the proliferative activity marker Ki-67 (10-70%), enhancement of activation (CD30, CD25), loss of some linear T-cell markers. Treatment of lymphosarcoma arising on the background of lingering MF or SD may combine two types of antitumor treatment - intensive and supporting because of coexistence of different clones of one tumor.
Conclusion. Verification of skin T-cell lymphoma diagnosis and its transformation into lymphosarcoma must be based on the evidence from a number of examinations: histological, immunophenotyping, moleculobiological and clinical. Among criteria of the transformation, markers of lymphoproliferative activation are of great importance.

T-cell skin lymphomas, mycosis fungoides, Sezary's syndrome, tumor progression, immunohistochemical markers of T-cell lymphoma