[Post-traumatic basal cell carcinoma associated with patch testing].

Basal cell carcinoma is the most common epithelial skin cancer in humans and usually effects elderly individuals. Although the pathogenesis is directly related to exposure to ultraviolet sunlight, other factors,particularly trauma, may be involved. We present the case of a woman with contact dermatitis due to sensitization to metals. She developed superficial basal cell carcinoma at the same site as a patch test-performed 30 months earlier-that was strongly positive to 1 % gold chloride. In the histologic study with a scanning electron microscope, we detected electron-dense particles in the dermis which were subsequently identified as gold.