VISHNU PRIYA ANGURAJTSMUGrp-14

BASAL CELL CARCINOMA

Basal cell carcinoma (BCC) is a slow progressing nonmelanocytic skin cancer

that arises from basal cells (ie, small, round cells found in the lower layer of the epidermis).

It is the most common skin cancer (80%)Estimated 3.3 million cases are diagnosed per

year(US) and incidence doubles every 25 years

The incidence high in areas of ↑UV radiation (Australia,South africa)estimated lifetime risk of 33-39% for men

and 23-28% for womenMen >WomenIt increases with age (50-80 yrs )Rare in <40 yrs (5-15%)

BCC

RISK FACTORS

Sun damage Repeated prior episodes of sunburn

Fair skin, blue eyes and blond or red hair ( also affect darker skin types)

Previous cutaneous injury, thermal burn, disease (eg cutaneous lupus, sebaceous naevus)

Inherited syndromes: BCC is a particular problem for families with basal cell naevus syndrome (Gorlin syndrome), Bazex syndrome, Rombo syndrome and xeroderma pigmentosum ,albinism

Other risk factors include ionising radiation, exposure to arsenic, coal tar, smoking tanning bed and immune suppression due to disease or medicines

The cause of BCC is multifactorial.DNA mutations in the patched

(PTCH) tumour suppressor gene, part of hedgehog signalling pathway (SHH)

triggered by exposure to ultraviolet radiationVarious spontaneous and inherited gene

defects predispose to BCC

ETIOLOGY AND PATHOGENESIS

SONIC HEDGEHOG PATHWAY

BCC is a locally invasive skin tumour and rarely metastatize(< 0.01%)

The main characteristics are:Slow growing: 0.5 cm in 1-2 yearsVaries in size from a few millimetres to

several centimetres in diameterSkin coloured, pink or pigmentedSpontaneous bleeding or ulcerationWaxy papules with central depressionPearly appearance

Oozing or crusted areas: In large BCCsRolled (raised) borderTranslucencyTelangiectases over the surfaceBlack-blue or brown areas

BCC distrubution :Head and neck 60%Nose 14%Trunk 30%Extremities 10%

There are several distinct clinical types of BCC, and over 20 histological growth patterns of BCC

NodularSuperficialMorphoeicBasisquamousFibroepithelial tumour of Pinkus

TYPES OF BCC

Most common type of facial BCCShiny or pearly nodule with a

smooth surface  with telangiectasesMay have central depression or

ulceration, so its edges appear rolledCystic variant is soft, with jelly-like

contentsMicronodular, microcystic and

infiltrative types are potentially aggressive subtypes

Nodular BCC

Most common type in younger adults

Most common type on upper trunk and shoulders

Slightly scaly, irregular plaqueThin, translucent rolled borderMultiple microerosions

SUPERFICIAL BCC

Also known as morphoeiform or sclerosing BCC

Usually found in mid-facial sitesWaxy, scar-like plaque with indistinct

bordersFlat or slightly depressed, fibrotic,

and firmWide and deep subclinical extension

MORPHOEIC BCC

Mixed basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)

Infiltrative growth patternPotentially more aggressive than other forms

of BCC

BASISQUAMOUS BCC

Warty plaqueUsually on trunk

Fibroepithelial tumour of Pinkus

SuperficialNodularMicronodularInfiltrating Sclerosing/ morpheaform MetatypicalInfundibulocystickeratotic AdenoidCystic basalPigmented

OTHER HISTOLOGICAL SUBTYPES

Characteristics of recurrent BCC often include:

Incomplete excision or narrow margins at primary excision

Morphoeic, micronodular, and infiltrative subtypes

Location on head and neck

Recurrent BCC

Advanced BCCAdvanced BCCs are large, often neglected

tumours.They may be several centimetres in diameterThey may be deeply infiltrating into tissues

below the skinThey are difficult or impossible to treat

surgically

Nevi malignant melanomaKeratoacanthomaSeborrheic keratosisBowen diseaseActinic keratosisSquamous cell carcinoma

DIFFERENTIAL DIAGNOSIS

Skin biopsyTo confirm and diagnose bcc and its

subtype Shave biopsy Punch biospy Cytology Histologic findings Laser doppler (eyelids tumor

margins)

Diagnosis

Treatment depends on size ,location and type of BCC

Curretage and electrosessicationMohs micrographic surgeryExcisional surgeryRadiationCryosurgeryPhotodynamic therayLaser surgeryTopical medications

TREATMENT

Curretage and electricdesiccation : The growth is scraped off with a curette, an instrument with a sharp, ring-shaped tip), then the tumor site is desiccated (burned) with an electrocautery needle.

Small lesionsLeaves round whiitish scarNot suitable for advanced bcc, in high

risk sites.

Excision means the lesion is cut out and the skin stitched up.

Most appropriate treatment for nodular, infiltrative and morphoeic BCCs

Should include 3 to 5 mm margin of normal skin around the tumour

Very large lesions may require flap or skin graft to repair the defect

Further surgery is recommended for lesions that are incompletely excised

Excisional surgery

MOHs SURGERY

Cryotherapy is the treatment of a superficial skin lesion by freezing it, usually with liquid nitrogen.

Suitable for small superficial BCCs on covered areas of trunk and limbs

Results in a blister that crusts over and heals within several weeks.

Leaves permanent white mark

CRYOTHERAPY

Photodynamic therapy (PDT) refers to a technique in which BCC is treated with a photosensitising chemical, and exposed to light several hours later.

Topical photosensitisers include aminolevulinic acid lotion and methyl aminolevulinate cream

Suitable for low-risk small, superficial BCCsResults in inflammatory reaction, maximal 3–4

days after procedureTreatment repeated 7 days after initial treatmentExcellent cosmetic results

PHOTODYNAMIC THERAPY

Radiotherapy or X-ray treatment can be used to treat primary BCCs or as adjunctive treatment if margins are incomplete.

Mainly used if surgery is not suitableBest avoided in young patients and in genetic

conditions predisposing to skin cancerBest cosmetic results achieved using multiple fractionsTypically, patient attends once-weekly for several

weeksCauses inflammatory reaction followed by scarRisk of radiodermatitis, late recurrence, and new

tumours

RADIOTHERAPY

Imiquimod creamImiquimod is an immune response modifier.Best used for superficial BCCs less than 2 cm diameterApplied three to five times each week, for 6–16 weeksFluorouracil cream5-Fluorouracil cream is a topical cytotoxic agent.Used to treat small superficial basal cell carcinomasRequires prolonged course, eg twice daily for 6–12

weeksCauses inflammatory reactionHas high recurrence rates

TOPICAL MEDICATIONS

SURGERY TARGET THERAPY (SHH PATHWAY

INHIBITORS)Vismodegib  (Erivedge™) Sonidegib  (Odomzo®)

Tx ADVANCED BCC

 Protect skin from sun exposure daily, year-round and lifelong.

Stay indoors or under the shade in the middle of the day

Wear covering clothingApply high protection factor SPF50+ broad-

spectrum sunscreens generously to exposed skin if outdoors

Avoid indoor tanning (sun beds, solaria)

PREVENTION

THANK YOU!