SKIN CANCERSKIN CANCER

DR D Czarnecki MD MB BSDR D Czarnecki MD MB BS

Premalignant lesionsPremalignant lesions

• Solar keratosesSolar keratoses

• SCC-in-situSCC-in-situ (also called) (also called)

Bowen’s diseaseBowen’s disease

Erythroplasia of QueyratErythroplasia of Queyrat

LeukoplakiaLeukoplakia

SOLAR KERATOSISSOLAR KERATOSIS

SCC-in-situSCC-in-situ

SQUAMOUS CELL CARCINOMASQUAMOUS CELL CARCINOMA

Premalignant lesionsPremalignant lesions

• Solar keratosesSolar keratoses – the abnormal cells are located – the abnormal cells are located above the basement membrane. above the basement membrane.

• SCC-in-situSCC-in-situ – the entire epidermis has abnormal – the entire epidermis has abnormal cells but the basement membrane is not penetrated. cells but the basement membrane is not penetrated. Abnormal cells are present in the appendages but do Abnormal cells are present in the appendages but do not penetrate into the dermis.not penetrate into the dermis.

• A squamous cell carcinoma is present when the A squamous cell carcinoma is present when the abnormal cells penetrate through the basement abnormal cells penetrate through the basement membranemembrane

Solar keratosesSolar keratoses

Premalignant lesionsPremalignant lesions

• Solar keratosesSolar keratoses – the lesions are scaly and red. The – the lesions are scaly and red. The margin is often poorly defined. The scale can be thin margin is often poorly defined. The scale can be thin or thick butor thick but

There is no thickening of the underlying dermisThere is no thickening of the underlying dermis

• SCC-in-situSCC-in-situ – the lesion is well demarcated but the – the lesion is well demarcated but the underlying tissue is not thick.underlying tissue is not thick.

• A squamous cell carcinoma thick (the underlying A squamous cell carcinoma thick (the underlying tissue is thick when squeezed)tissue is thick when squeezed)

Bowen’s disease – SCC-in-situBowen’s disease – SCC-in-situ

An SCC next to a seborrhoeic keratosisAn SCC next to a seborrhoeic keratosis

Solar keratosesSolar keratoses

• Solar keratoses are premalignant lesionsSolar keratoses are premalignant lesions

• Studies in different countries have come up with Studies in different countries have come up with similar findingssimilar findings

• About 1 in 6 About 1 in 6 people with SKs will develop an SCC in people with SKs will develop an SCC in the affected area within 5 yearsthe affected area within 5 years

• SCCs that develop in sun damaged skin are just as SCCs that develop in sun damaged skin are just as likely to metastasize as those that develop de novolikely 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 keratosesSolar keratoses

• There is no reliable evidence that SKs disappearThere is no reliable evidence that SKs disappear – – studies that claimed that the disappear relied on studies that claimed that the disappear relied on counting lesions. The investigators could not agree counting lesions. The investigators could not agree among themselves how many SKs there were.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 steroid5FU and a fluorinated steroid – for the face, scalp – for the face, scalp earsears

• Cryotherapy – hands, arms, etc where the skin is Cryotherapy – hands, arms, etc where the skin is thickerthicker

Solar keratosesSolar keratoses

• 5 fluoro-uracil (5FU) will destroy SKs but it is 5 fluoro-uracil (5FU) will destroy SKs but it is irritating if used on its ownirritating if used on its own

• Patients apply a fluorinated steroid cream after Patients apply a fluorinated steroid cream after applying 5FUapplying 5FU

• The creams are applied at night, each night for 25 The creams are applied at night, each night for 25 nightsnights

• 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 cryotherapyBlisters after cryotherapy

SCC-in-situSCC-in-situ

• This can occur on mucous membranes. SCCs that This can occur on mucous membranes. SCCs that arise in SCC-in-situ are more likely to metastasize arise in SCC-in-situ are more likely to metastasize than SCCs that arise in solar keratosesthan 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 Imiquimod can be used on some sites – such as the – such as the penispenis

SCC-in-situSCC-in-situ

Also called:Also called:

Erythroplasia of QueyratErythroplasia of Queyrat

SCCs in the genitalia have SCCs in the genitalia have a high metastatic ratea high metastatic rate

LeukoplakiaLeukoplakia

SCC-in-situSCC-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 effectiveImiquimod is effective if used on selected lesions if used on selected lesions

thin lesions on thin skinthin lesions on thin skin

• Confirm the diagnosisConfirm the diagnosis

biopsybiopsy

SCC-in-situSCC-in-situ

Confirmed by biopsy

Four years after imiquimod was usedFour years after imiquimod was used