Solar Keratosis
Pathology
- Solar keratosis: squamous cell carcinoma in situ
- AKA senile or actinic keratosis
- Histological appearance include
- Hyperkeratosis (thickening of the keratin layer)
- Focal parakeratosis
- Irregular acnathosis (thickening of the prickle layer)
- Basal layer atypia only
- Risk of progression to malignancy: 25% if untreated
Approach
- Examine as for any lump
- Inspection
- Usually multiple
- Yellow-grey or brown in colour
- Begin with thickening of the skin which can become unsightly and catch on clothing
- Scaly surface
- Can occur as a "solar horn" on the pinna or the ear
- Palpation
Completion
- Ask about similar lesions elsewhere
- How the lesion affects life
Treatment:
- Non-surgical
- Cryotherapy
- Topical application of 5-FU (fluorouracil)
- Retinoic acid (to reverse the damaging effects of sunlight)
- Surgical
- Shaving off affected skin
