Two cases of phenotypic switch of primary cutaneous T cell lymphoma after treatment with an aggressive course and review of the literature

We report two cases of pa tients that were diagnosed with a CD4+ mycosis fungoides with positive T cell receptor gene rearrangement studies. Both patients originally responded to treatment, but subsequently, their CTCL came back with a different phenotype of a CD4− CTCL. Gene rearrangement studies were performed on the sec ond occurrence in order to prove that this was the same lymphoma. Both patients died from their CTCL. Additionally, we collected seven cases of primary CTCL from the literature with tissue samples from before and after treatment with molecular studies confirming these neoplasms contained the same T cell clone, providing evidence of a true PS. This too revealed a poor prognosis in the majority of these cases. CTCL should be worked up to determine whether a PS has occurred after therapy since it could confuse management of patients and appears to portend a poor prognosis.
Source: Virchows Archiv - Category: Pathology Source Type: research