Can actinic keratosis turn into a mole and what happens if it becomes elevated?

Actinic Keratosis Does Not Transform Into Moles

Actinic keratosis (AK) cannot turn into a mole—these are completely different lesion types with distinct cellular origins. AKs are dysplastic keratinocyte proliferations that may progress to squamous cell carcinoma (SCC), while moles (nevi) are melanocytic lesions 1.

Understanding What Actinic Keratosis Actually Is

AKs are premalignant keratinocyte lesions, not melanocytic lesions:

• AKs represent focal areas of abnormal keratinocyte proliferation and differentiation with epithelial dysplasia 1
• The cardinal histological feature is epithelial dysplasia that may be restricted to the basal layer or extend to full-thickness atypia (at which point it becomes SCC in situ/Bowen disease) 1
• Histological variants include hypertrophic, bowenoid, lichenoid, acantholytic, and pigmented types 1, 2

Moles are melanocytic proliferations—an entirely different cell lineage with no relationship to AKs.

What Elevation of an Actinic Keratosis Actually Means

When an AK becomes elevated or thickened, this is a concerning sign that warrants immediate evaluation:

• Elevation suggests progression to hypertrophic AK or possible transformation to invasive SCC 1
• Any lesion that bleeds, is painful, grows significantly, or becomes protuberant requires urgent assessment for possible SCC 1
• Hypertrophic or elevated AKs that fail to respond to standard therapy should undergo biopsy or excision for histological examination 1

The Real Risk: Progression to Squamous Cell Carcinoma

The actual concern with AKs is malignant transformation to SCC, not conversion to moles:

• Less than 1 in 1000 AKs develops into SCC per year 1
• For patients with an average of 7.7 AKs, the probability of developing an SCC within 10 years is approximately 10% 1
• Patients with ≥10 AKs have a threefold higher risk of SCC compared to those with 4-9 lesions 1

Critical Clinical Pitfall to Avoid

The pigmented variant of AK can be confused with melanocytic lesions, but this does not mean AKs transform into moles:

• Pigmented AKs are a recognized histological variant but remain keratinocyte-based lesions 1, 2
• Uncertainty may arise in distinguishing AKs from superficial basal cell carcinoma, SCC in situ, invasive SCC, or even amelanotic melanoma—in these cases, biopsy is indicated 1
• If there is diagnostic uncertainty between an AK and a melanocytic lesion, biopsy is mandatory 1

When to Worry About Elevation

Elevated or changing AKs require more aggressive management:

• Hypertrophic AKs are best treated with curettage or may require formal excision with histology 1
• Isolated lesions failing to respond to other therapies should undergo biopsy, as histology may be required to rule out invasive malignancy 1
• Patient care should be shared with a skin cancer multidisciplinary team when invasive malignancy is in the differential 1