Disseminated superficial actinic porokeratosis before and after treatment with radiation therapy

(A, B) Before treatment – DSAP presenting on the lower leg as multiple erythematous macules with hyperkeratotic rim at the periphery (marked fields for radiotherapy with grenz rays).
(C, D) Lower leg 16 months after the treatment with grenz rays (32 Gy in 8 sessions, 10 kV). DSAP lesions are still present on the knee area.
(E, F) Knee area 2 months after treatment with grenz rays (28 Gy in 7 sessions, 10 kV). Note postradiotherapy transitory hyperpigmentation of the knee area. The hyperpigmentation resolves spontaneously over time, as shown on the lower area of the leg that was treated 18 months earlier.