JAMES M.GRICHNIKMD, PhD
The lesions are from the lower back of a 67-year-old woman (Figure 1), the lower abdomen of a 47-year-old woman (Figure 2) (scales show millimeters), and the lower back of a 60-year-old man (Figure 3). All 3 lesions reveal a similar pattern. Note the presence of brown-gray and blue-gray localized coarse granules with areas of remaining seborrheic keratosis. The brown-gray and blue-gray localized and diffuse granular pattern is typical of lichen planus–like keratosis or benign lichenoid keratosis. It has been suggested that lichen planus–like keratosis may be the inflammatory stage of regressing benign but also malignant skin tumors, mainly solar lentigines and seborrheic keratosis. These cases illustrate the intermediate stage of this phenomenon in 3 examples of seborrheic keratosis.
Zaballos P, Martí E, Cuéllar F, Puig S, Malvehy J. Dermoscopy of Lichenoid Regressing Seborrheic Keratosis. Arch Dermatol. 2006;142(3):410. doi:10.1001/archderm.142.3.410