RAPID DEVELOPMENT OF DISSEMINATED SUPERFICIAL POROKERATOSIS AFTER TRANSPLANT INDUCTION THERAPY

Disseminated superficial actinic porokeratosis (DSAP) is a cutaneous d isorder, usually inherited in an autosomal dominant fashion, character ized by numerous annular papules with subtle raised hyperkeratotic bor ders and slightly atrophic centers. While the precise pathophysiologic mechanisms underlying the development of DSAP are unknown, one hypoth esis is multifocal expansion of atypical clones of keratinocytes, perh aps unmasked by actinic damage, as implied by its name. Although prima rily of cosmetic concern, there is an increased risk of squamous cell carcinoma of the skin developing within DSAP lesions, which often show histologic keratinocytic atypia centrally. Immunosuppression, which i s a significant risk factor for secondary malignancies including cutan eous squamous cell carcinoma, is also a well-documented precipitant of porokeratosis. We report a 62-year-old man who developed DSAP in a wi dely and rapidly progressive manner within days of receiving total bod y radiation and high-dose induction chemotherapy as planned preparativ e therapy for an autologous peripheral blood stem cell transplant for relapsed high grade lymphoma. Our patient's eruption of DSAP highlight s a little recognized cutaneous manifestation of aggressive bone marro w transplant induction therapy.