Unilateral mycosis fungoides.

We present an unusual case of unilateral mycosis fungoides (MF) in a 38-year-old woman. This woman presented to us because of multiple, localized, pruritic confluent plaques that appeared on the right-side of her chest and back 8 years ago. Skin biopsies showed characteristic findings of mycosis fungoides (e.g., Pautrier microabscesses, follicular epitheliotropism, wiry bundles of collagen, etc.). T-cell receptor gene rearrangement analysis in the lesional skin demonstrated rearrangement of the gamma chain. PUVA therapy improved her skin lesions and pruritus, but these plaques progressed again after discontinuation of treatment. We conclude that MF can be localized and unilateral. Thus, a high index of suspicion is necessary for diagnosis of this potentially lethal disease.