Mycosis fungoides presenting as keratosis lichenoides chronica.

We report a patient with a 17-year history of reticulated keratotic papules on the trunk and limbs, and telangiectatic eruption on the face, in whom the diagnosis of keratosis lichenoides chronica was first established. However, the biopsies showed an epidermotropic infiltrate of small irregular CD4+ lymphocytes, and detection of a T-cell clone in the lesions by polymerase chain reaction confirmed the diagnosis of mycosis fungoides. Thus, keratosis lichenoides chronica can be an unusual and potentially misleading presentation of mycosis fungoides.