SKIN CANCER DR D Czarnecki MD MB BS

Premalignant lesions Solar keratosesSolar keratoses SCC-in-situ (also called)SCC-in-situ (also called) Bowen’s disease Bowen’s disease Erythroplasia of Queyrat Erythroplasia of Queyrat Leukoplakia Leukoplakia

SOLAR KERATOSIS SCC-in-situ SQUAMOUS CELL CARCINOMA

Premalignant lesions Solar keratoses – the abnormal cells are located above the basement membrane.Solar keratoses – the abnormal cells are located above the basement membrane. SCC-in-situ – the entire epidermis has abnormal cells but the basement membrane is not penetrated. Abnormal cells are present in the appendages but do not penetrate into the dermis.SCC-in-situ – the entire epidermis has abnormal cells but the basement membrane is not penetrated. Abnormal cells are present in the appendages but do not penetrate into the dermis. A squamous cell carcinoma is present when the abnormal cells penetrate through the basement membraneA squamous cell carcinoma is present when the abnormal cells penetrate through the basement membrane

Solar keratoses

Premalignant lesions Solar keratoses – the lesions are scaly and red. The margin is often poorly defined. The scale can be thin or thick butSolar keratoses – the lesions are scaly and red. The margin is often poorly defined. The scale can be thin or thick but There is no thickening of the underlying dermis There is no thickening of the underlying dermis SCC-in-situ – the lesion is well demarcated but the underlying tissue is not thick.SCC-in-situ – the lesion is well demarcated but the underlying tissue is not thick. A squamous cell carcinoma thick (the underlying tissue is thick when squeezed)A squamous cell carcinoma thick (the underlying tissue is thick when squeezed)

Bowen’s disease – SCC-in-situ

An SCC next to a seborrhoeic keratosis

Solar keratoses Solar keratoses are premalignant lesionsSolar keratoses are premalignant lesions Studies in different countries have come up with similar findingsStudies in different countries have come up with similar findings About 1 in 6 people with SKs will develop an SCC in the affected area within 5 yearsAbout 1 in 6 people with SKs will develop an SCC in the affected area within 5 years SCCs that develop in sun damaged skin are just as likely to metastasize as those that develop de novoSCCs that develop in sun damaged skin are just as likely to metastasize as those that develop de novo

A solar keratosis (cutaneous horn) The thickening is dead skin The underlying tissue is not thick

Solar keratoses There is no reliable evidence that SKs disappear – studies that claimed that the disappear relied on counting lesions. The investigators could not agree among themselves how many SKs there were.There is no reliable evidence that SKs disappear – studies that claimed that the disappear relied on counting lesions. The investigators could not agree among themselves how many SKs there were. Remove solar keratoses before they turn into SCCsRemove solar keratoses before they turn into SCCs 5FU and a fluorinated steroid – for the face, scalp ears5FU and a fluorinated steroid – for the face, scalp ears Cryotherapy – hands, arms, etc where the skin is thickerCryotherapy – hands, arms, etc where the skin is thicker

Solar keratoses 5 fluoro-uracil (5FU) will destroy SKs but it is irritating if used on its own5 fluoro-uracil (5FU) will destroy SKs but it is irritating if used on its own Patients apply a fluorinated steroid cream after applying 5FUPatients apply a fluorinated steroid cream after applying 5FU The creams are applied at night, each night for 25 nightsThe creams are applied at night, each night for 25 nights The SKs become inflamed before they disappearThe SKs become inflamed before they disappear

A typical 5 FU reaction He had no idea that there were so many SKs

Blisters after cryotherapy

SCC-in-situ This can occur on mucous membranes. SCCs that arise in SCC-in-situ are more likely to metastasize than SCCs that arise in solar keratosesThis can occur on mucous membranes. SCCs that arise in SCC-in-situ are more likely to metastasize than SCCs that arise in solar keratoses Different terms are usedDifferent terms are used Treatment is difficultTreatment is difficult Imiquimod can be used on some sites – such as the penisImiquimod can be used on some sites – such as the penis

SCC-in-situ Also called: Erythroplasia of Queyrat SCCs in the genitalia have a high metastatic rate

Leukoplakia

SCC-in-situ 5 fluoro-uracil (5FU) has a high failure rate5 fluoro-uracil (5FU) has a high failure rate Surgery is effectiveSurgery is effective Imiquimod is effective if used on selected lesionsImiquimod is effective if used on selected lesions thin lesions on thin skin thin lesions on thin skin Confirm the diagnosisConfirm the diagnosis biopsy biopsy

SCC-in-situ Confirmed by biopsy

Four years after imiquimod was used