Pathological features of actinic keratoses showing alternating parakeratosis and hyperkeratosis.
Dermoscopy showing thickened warty appearance of seborrhoeic keratosis.
Solitary basal cell carcinoma with pearly edge and minimal hyperkeratosis.
Actinic keratosis (AK) management algorithm. *Treatment should be decided following discussion with the patient, assessment of treatment availability ...
Cutaneous horn with low height‐to‐base ratio. Pathology showed squamous cell carcinoma at the base.
Pathology of Bowen disease showing loss of polarity of the epidermis and the presence of atypical mitoses and giant cells.
Superficial basal cell carcinoma mimicking Bowen disease.
(a) Large confluent areas of bowenoid papulosis. (b) Following treatment for 6 weeks with 5% imiquimod cream. (c) Marked improvement seen at follow‐up...
Key signalling pathways involved in the formation of squamous cell carcinomas (SCCs). Mutations induced by UVB exposure can perturb multiple cellular ...
Well‐differentiated squamous cell carcinoma with even circumscribed edge and central crusting.
Squamous cell carcinoma (SCC) management algorithm. (Annex 3 reproduced and adapted with permission from the Scottish Intercollegiate Guidelines Netwo...
Squamous cell carcinoma showing hyperkeratosis with a raised nodule.
‘Low‐risk’ disease characterized by few thin actinic keratoses.
(a) Actinic keratoses before treatment with 5% 5‐fluorouracil cream. (b) Three weeks into treatment with daily 5% 5‐fluorouracil cream. (c) Post‐treat...
Pathology of post‐ionizing radiation keratosis.
Squamous cell carcinoma with hyperkeratosis and raised thickened edge.
Dermoscopy of Bowen disease showing irregular erythematous base, mild hyperkeratosis with vascular structures throughout the lesion.
Pathological features of well‐differentiated, early invasive squamous cell carcinoma, showing differentiated keratinocytes invading the underlying der...
Seborrhoeic keratosis mimicking squamous cell carcinoma.
(a) Pathology of keratoacanthoma showing endophytic growth pattern with epidermal lipping and no evidence of dermal invasion (×20). (Courtesy of Dr M...
Lichenoid actinic keratoses.
Bowen disease which is usually larger than actinic keratoses with an irregular erythematous base.
‘High‐risk’ disease characterized by multiple thick actinic keratoses and previously excised non‐melanoma skin cancer.
(a) Hyperkeratotic actinic keratosis before treatment with 5% imiquimod cream. (b) Four weeks into treatment with 5% imiquimod cream. (c) Post‐treatme...
Cornoid lamella with parakeratotic column overlying epidermal dyskeratotic and vacuolated cells, representing the clinically visible raised margin see...
Multiple areas of Bowen disease on the lower leg.
Discoid dermatitis of the lower leg. (Courtesy of Dr W. A. D. Griffiths, Epsom Hospital, Surrey, UK.)
Bowen disease management algorithm. *Treatment should be decided following discussion with patient, treatment availability and local expertise with th...
Multiple invasive squamous cell carcinomas in a patient with a history of exposure to arsenic.
Well‐differentiated squamous cell carcinoma on the helix of the ear (high‐risk site).
Scarring seen in a patient with multiple self‐healing squamous epitheliomas.
(a,b) Keratoacanthoma which is often larger and more hyperkeratotic than actinic keratosis.
‘High‐risk’ disease characterized by multiple thick actinic keratoses in an immunosuppressed patient on ciclosporin.
Typical cutaneous horn. Underlying this lesion, a carcinoma in situ was identified after biopsy.
Disseminated superficial actinic porokeratosis on the lower legs.
Periungual Bowen disease.
(a,b) Plaque with thick scale. Examination elsewhere shows typical scaly plaques seen in psoriasis.
(a) Bowen disease before treatment with liquid nitrogen cryotherapy. (b) Dermoscopy prior to treatment, showing crusting with central vascular structu...
Raised erythematous invasive squamous cell carcinoma in an elderly patient on a light‐exposed site.
Poorly differentiated squamous cell carcinoma presenting as a nodule and lacking typical keratin centre.