Primary cutaneous T cell lymphomas: photochemotherapy immunomodulation with analysis of the inflammatory‐expansive cellular dynamic

Primary cutaneous T cell lymphomas (CTCLs) are characterized by hyperproliferation of malignant CD4+ T cells with primary localization on the skin. The common characteristics are the migration of the malignant mature T‐lymphocytes into the epidermis, with hyperproliferation of malignant CD4+ T cells and epidermotropism. Sézary syndrome (SS) is the leukemic variant. It was established that CTCLs arise from a clonal expansion of CD4+ T cells with an identical rearrangement of the T cell receptor. The purpose of this study was to evaluate the immunomodulation effect of photochemotherapy‐A (psoralen plus ultraviolet A (PUVA)). Pre‐ and post‐PUVA punch skin biopsies of nine patients were stained immunohistochemically for CD34+, CD8+, CD7+, CD16+, CD56+, CD1a+, Bcl2+, p53+, CD45RA+, and CD45RO+ cells. The results showed a pre‐PUVA cells/mm² without significant difference among expansive or reactive cells. Post‐PUVA analysis showed a significant decrease in the mean of expansive‐reactive cells. PUVA immunomodulated decreasing cellular infiltrate. These findings could contribute to the comprehension of how PUVA acts. We achieved ectoscopic clearance of the lesions, although post‐PUVA, there still was a mononuclear pathological infiltrate. This result demonstrates that the PUVA treatment should only be withheld when the histological analysis is normal.