Benign Keratosis: A Useful Term?

INTRODUCTION: Seborrheic keratosis (SK), lichen planus-like keratosis (LPLK), and solar lentigo (SL) are common benign skin lesions. These lesions are frequently seen adjacent to each other or can arise from one another. They can sometimes be difficult to differentiate despite having distinct histopathological features. OBJECTIVES: We evaluated dermoscopic images of 80 skin lesions to confirm the term ‘benign keratosis’ is useful for an undifferentiated SK/LPLK/SL where there are overlapping clinical and dermoscopic characteristics. METHODS: Clinical and dermoscopic images were sourced from a teledermoscopy service database of 13,000 lesions in 7,000 patients. The database was queried for SK, SL or LPLK in sun-exposed sites. Each lesion was evaluated based on specific dermoscopic criteria and the results analyzed. RESULTS: Lesions were identified with mixed clinical and dermoscopic criteria of SK and SL, and in some, dermoscopic criteria for LPLK were also present. CONCLUSIONS: This study highlights the relationship between these lesions. We confirm the term ‘benign keratosis’ is useful for mixed lesions or for those that are difficult to classify.