RESUMEN
Two ulcerated basal cell carcinomas of the right lower leg developed almost 50 years after a psoriasis had been treated by oral arsenic therapy. While repeated biopsies proved negative, the lesions were thought to be chronic venous ulcers. During conservative treatment for 8 years, both ulcers showed slow progression. Multiple, aggressive biopsies revealed finally two basal cell carcinomas. Treatment consisted of radical excision of involved soft tissue and tibial bone. Closure of the resulting defect was accomplished by muscle-transposition and meshgraft. Normal function of the right leg could be preserved. Spontaneous fracture of the right lower leg occurred 3 years after surgical treatment and amputation was necessary because of extensive local recurrence.