Pagetoid reticulosis consists of 2 types: Woringer-Kolopp and Ketron-Goodman disease (K-G). Compared with the former, K-G may have disseminated lesions and a guarded prognosis. We encountered a case of K-G in a 67-year-old man with disseminated plaques on the neck, the trunk, and both extremities. Histologic specimens demonstrated medium- to large-sized, atypical cells infiltrating in the lower epidermis. The phenotype (CD3+, CD4−, CD8−, CD45RO−, CD45RA+) and ultrastructural findings suggest that these cells were immature T cells. Although PUVA was initially effective, new plaques in which atypical cells are still present histologically, have appeared through a 6-year follow-up. Literature review revealed the high rate of recurrence. These findings suggest that K-G is an epidermotropic or immature T-cell variant of mycosis fungoides. In patients with K-G, therefore, long-term observation is necessary: Disappearance of cutaneous lesions may not mean cure. (J Am Acad Dermatol 2002;47:S183-6.)Le texte complet de cet article est disponible en PDF.