Tumours - Skin Neoplasia

Other Tumours

Benign

·        Epidermal cyst: 

o  Collection of epidermal cells within the dermis. Either around the base of a hair follicle or from trauma (eg on a builders hands) 

o   If it becomes infective ® ulcerates and smells

o   May be tethered to the epidermis with a central keratin filled punctum

o   Treatment: surgical excision for cosmetic or nuisance reasons

·        Seborrhoeic Keratosis ( = Basal cell papilloma) 

o   ­ Incidence with age, sun exposure, familial tendency, often associated with skin tags

o   Raised, sharply demarcated papule or plaque, shiny, bleeds easily if scrapped.  Variable size, 

o   „stuck on‟ appearance with cobblestone or leathery appearance, skin coloured, yellowish or greyish brown/black 

o   Results from proliferation of squamous basaloid cells which sit on top of and do not invade the dermis (grow up, compared to BCC which grows down) 

o   Histology: hyperkeratosis, well circumscribed, cystic structures within the epidermis filled with keratin

o   Treatment: liquid nitrogen for cosmetic reasons.  Fairly harmless

o   Differential:

§  Melanoma – but different surface texture

§  Pigmented solar keratosis: treatment similar so differential not so important

·        Keratoacanthoma:

o   Uncommon 

o   On lip, up to 1 cm. Other areas up to 2 cm. Develops quickly (eg 4 weeks – too fast to be an SCC) then heals with a scar 

o   A „self healing squamous cell carcinoma‟.  Inflammatory reaction at the base – body is rejecting it

·        Dermatofibroma (= sclerosing haemangioma):

o   Slightly elevated and pink or brown.  Firm, button-like dermal lesion.  Usually female

o   Histology: expands into dermis

o   Not malignant – but recurs if not all cut out

Premalignant Lesions

·        Actinic keratosis (= Solar Keratosis)

o   Common: 50% of NZers over 65 

o   In situ proliferation of dysplastic squamous epidermal cells caused by UV light. Often on face, white

o   Adherent scale, difficult to pick off.  Not well circumscribed.  Erythematous base 

o   May spread within the epidermis, stop growing, recede or progress to invasive squamous cell carcinoma (only 1%) 

o   Histology: large, irregular nuclei, overgrowth of epidermis, hyperkeratosis and parakeratosis 

o   Indicates sun damage has occurred ® person at ­ risk of SCC, BCC and melanoma 

o   No evidence that removal reduces the incidence of cancer – don‟t need to treat but often do for cosmetic reasons

o   Differential:

§  Bowen‟s Disease: usually larger with a sharper margin 

§  Discoid Lupus: erythema or pigmentation more marked, may have a pitted surface, more common in Polynesians

o   Treatment:

§  Reduce sun exposure

§  Examine skin regularly for cancer

§  Remove lesions which are atypical, growing, annoying, unsightly

§  Liquid nitrogen if few in number 

§  Efudix (5FU) cream: good for treating a large area – goes red and sore, stop cream then resolution. If you use the cream too long ® ulcers, etc

§  Also retinoic acid, laser resurfacing, imiquimod (expensive)

·        Bowen‟s Disease:

o   More uncommon – but at least as common as SCC

o   75% are on the leg

o   Erythematous, well circumscribed, 1cm or more 

o   Slightly raised plaque with irregular hyperkeratosis. Compared with BCC it‟s not so shiny and has no pearly rim. May be bright red 

o   May remain stable for a long time. If growing or bleeding or young patient ® treat. SCC arises in 3% 

o   Differential:

o   Solar keratosis

o   BCC: shiny surface, pearly border, few dots of pigment

o   Psoriasis: silvery scale

o   Eczema

·        Treatment:

o   Excision

o   Liquid nitrogen – need more aggressive freeze than SK, on leg may ulcerate

o   Leave and watch

Malignant

·        Basal cell carcinoma:

o  Most common malignant tumour

o  Nodular BCC: 

§  Flat and paler than surrounding skin, pearly or translucent, shiny. May have telangiectases over the surface

§  Progresses to „rodent ulcer‟ (ulcer with raised, rolled edges)

§  Often on bridge of nose where glasses sit

§  Differential:

·        Intradermal naevus: Don‟t have the shiny, stretched look of a BCC

·        SCC: usually in badly damaged skin, and not translucent

o  Superficial BCC: 

§  Red plaque +/- atrophy +/- dots of pigment. Usually well circumscribed. Raised rim. Less shiny. Commonest on back, arms, legs, behind ears

§  Most common form of BCC

§  Differential:

·        Eczema: weepy, fissured surface, itchy (BCC isn‟t), atypical sites for a BCC

·        Psoriasis: silvery scale

·        Bowen‟s disease: duller surface with more hyperkeratosis

o  Don‟t metastasis but does invade.  Won‟t kill you (at least quickly)

o  Histology: basophilic (blue) cells, palisaded around the edge

·        Squamous cell carcinoma:

o  Skin coloured or purplish nodule/plaque which may ulcerated 

o  On badly sun damaged skin – dorsum of the hand, bald scalp, lower lip (BCC‟s uncommon on these sites)

o  Surface may be hyperkeratotic or warty.  Margins less well defined than BCC 

o   May have cutaneous horn.  Fleshy layer at the base of the horn differentiates it from benign lesions

o  Commonly misdiagnosed as BCC

o  If neglected will invade (claw-like infiltration)

o  4% metastasise

o  On sun exposed areas, may have cutaneous horns

o  Histology: hyperkeratosis