A 57-year-old woman complained about a cluster of “sores” on her chest. Her past history included treatment for a small number of actinic keratoses and a single basal cell carcinoma of the face.
Key point: There are 3 red “spots” in close proximity. The differential diagnosis is quite wide, and includes folliculitis, seborrheic keratoses (inflamed), actinic keratoses, small superficial basal cell carcinomas, or small squamous cell carcinomas in-situ. This morphology is simply too nondescript to suggest a definitive diagnosis. Biopsy of all lesions showed lichenoid keratosis— a benign lesion, probably related to seborrheic keratosis, which often mimics skin cancer.
Treatment: No therapy is indicated for lichenoid keratosis. Light liquid nitrogen cryosurgery can be done to remove larger, cosmetically objectionable lesions.
Note: Lichenoid keratoses favor the upper arms, shoulders and chest.