Central nervous system involvement in patients with mycosis fungoides and cutaneous large-cell transformation.

Central nervous system (CNS) involvement in mycosis fungoides (MF) is a rare occurrence with devastating consequences. Large-cell transformation (LCT) of MF is associated with a poor prognosis and increased extracutaneous manifestations. In this report, we present 5 patients with MF, LCT, and CNS disease to better define their presentation, treatment, and prognosis and present critical differences they have compared with their nontransformed counterparts.