A man who had been circumcised in adulthood developed, in sequence, balanitis xerotica obliterans (lichen sclerosus et atrophicus), multiple dysplastic keratoses, and a superficial, well-differentiated squamous-cell carcinoma on the glans penis. Squamous-cell carcinoma that develops after circumcision in adulthood tends to be more aggressive in biologic behavior and more malignant-looking in histology. Cancer developing within lesions of lichen sclerosus et atrophicus has been reported rarely.