The notch sign as a clue for the diagnosis of early cutaneous T-cell lymphoma

We report a severe case of cutaneous T-cell lymphoma (CTCL) that progressed from an early plaque stage, undiagnosed for several years, to an advanced tumor stage with fatal consequences. Nevertheless, this case of mycosis fungoides (MF) could have been diagnosed at an earlier stage thanks to the presence of the notch sign in association with other clinical diagnostic signs of MF. The notch sign refers to the sometimes sharp, well-defined, notchlike demarcations of MF plaques. Although nonspecific, this sign is an additional aid to guide clinicians toward iterative skin biopsies to unmask MF.