Dermaimaging

In a 50-year-old woman, on the leg

What to see at dermoscopy:

-sharply demarcated and moth-eaten border
-fissures and ridges (cerebriform pattern)
-milia-like cysts

Dermoscopy in favor of early seborrheic keratosis

In a 73-year-old woman, on the leg 

What to see at dermoscopy:

-cerebriform pattern
-fissures and ridges
-sharp borders
-scar-like depigmentation (lower portion of lesion)
-scaly surface at the lower portion of lesion

Although dermoscopy is in favor of seborrheic keratoses,  biopsy at the lower portion of lesion was indicated to rule out a squamous cell carcinoma.
Hitopathology correlation: actinic keratoses.  

In 82-year-old woman, on the supraclavicular fossa

What to see at dermoscopy:

-sharply demarcated and irregular border (moth-eaten appearance); within the lesion, faint and irregular network
-structureless areas
-peppering at the edge of the lesion (regression areas)
-milia-like cysts and comedo-like openings
-cerebriform appearance at the upper right portion of the lesion
Dermoscopy signs in favor of lichen planus-like keratosis

Comments: lichen planus-like keratosis is believed to be either a solar lentigo or an early seborrheic keratosis undergoing regression; important to remember that it can simulate the early changes seen in lentigo maligna.

In a 64-year-old woman, on the chest

In a 44-year-old woman, on the upper back

What to see at dermoscopy:

-absence of pigmented network
-sharply demarcated border
-fissures and ridges [cerebriform pattern (generally associated with an acanthotic seborrheic keratosis)]
Dermoscopy signs in favor of seborrheic keratosis