A Case of Giant Seborrheic Keratosis

Abstract

A 74-year-old man was admitted to our hospital for the treatment of a tumor above his sternum. The tumor had been slowly enlarging for about 20 years and was a red-brown hyperkeratotic plaque, measuring 12×10cm at admission. By incisional biopsy, it was diagnosed as the clonal type of seborrheic keratosis. Later the tumor was excised and the defect was repaired with a split-thickness skin graft. Although cases of giant seborrheic keratoses larger than 3cm in diameter have rarely been reported, it should be noted that some authors have suggested the risk of malignant change.