Basal and Squamous Cell Carcinoma a review

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Basal and Squamous Cell Carcinoma - a review

• Trefor Nodwell MDCM
• Resident Division of Plastic Surgery
• Dalhousie University

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Overview

• Address BCC and SCC in regards to
• Skin embryology and Anatomy
• Epidemiology
• Pathophysiology and risk factors
• Clinical presentation
• Associated syndromes

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Overview

• Histopathology
• Pre-malignant lesions
• Management
• Outcomes
• Cases

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Primary Skin Malignancies

• Embryology-
• ectodermal derivatives
• epidermis, pilo-sebaceous and apocrine units
  eccrine sweat glands, nail units
• Neuro-ectoderm
• melanocytes, nerves, sensory receptors
• Mesoderm
• macrophages, mast cells, Langerhans cells, Merkel
  cells, fibroblasts, blood and lymph vessels, fat
  cells.

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Primary Skin Malignancies

• Anatomy
• Epidermis
• stratified squamous epithelium (keratinized)
• four cell types- keratinocytes, melanocytes,
  Langerhans cells and Merkel cells
• 0.04-1.4mm thick.

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Primary Skin Malignancies

• Dermis
• Primarily acellular.
• 15-40 times thicker than the epidermis
• Upper thin papillary layer
• Lower thicker reticular layer

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Primary Skin Malignancies Epidemiology

• 700-800 thousand cases in the US per annum
• 1 of all cancer deaths
• 77 BCC, 20 SCC, 3 melanoma and other
• Incidence increasing 3-7 per year in the white
  population
• Doubled between 1970-86

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Primary Skin Malignancies

• Pathophysiology
• Etiologic factors
• UV(B) exposure
• Therapeutic (Ionizing) Radiation Exposure
• Chemical Carcinogens
• Viral Carcinogens
• Multistep Hypothesis of Carcinogenesis
• Initiation
• Promotion
• Progression

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Primary Skin Malignancies

• Biophysical Risk factors
• Male
• White (Celtic Origin)
• Sunburn Easily
• Increasing Age
• Blue Eyes
• Fair Complexion

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Skin Phototypes
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Basal Cell Carcinoma
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Basal Cell Carcinoma

• Most Common Malignancy of whites
• Typically sporadic
• Immature cells of the Basal Layer, External root
  sheath of the hair follicle.
• No cellular anaplasia (a true carcinoma?)
• Rare metastasis

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Basal Cell Carcinoma - Subtypes

• Nodular Ulcerative
• Most common
• Usually on the face
• Small, slow growing
• Firm
• Telangectasias
• Ulceration

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Basal Cell Carcinoma - Subtypes

• Superficial
• Single or multiple patches
• Trunk
• Indurated scaly
• Differential - eczema, psoriasis or tinea.

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Basal Cell Carcinoma - Subtypes

• Sclerosing (Morpheaform)
• Yellow white plaques
• Ill defined boarders
• Most aggressive
• Most likely to recur
• Central sclerosis and scarring

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Basal Cell Carcinoma - Subtypes

• Pigmented
• Similar to nodular type
• Deep brown pigmentation
• Differential- malignant melanoma

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Basal Cell Carcinoma - Subtypes

• Fibroepithelioma
• Pinkus Tumour
• Raised
• Moderately firm
• Erythematous and smooth
• Lower trunk (lumbosacral area)_

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Basal Cell Carcinoma - Syndromes

• Basal Cell Nevus (Gorlins) Syndrome
• Autosomal Dominant, no sex linkage, low
  penetrance
• ? Mutated tumour suppressor at Ch 9q23.1-q31
• Childhood onset
• BCC (average age 20y)
• Pitting of palms and soles

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Basal Cell Carcinoma - Syndromes

• Basal Cell Nevus (Gorlins) Syndrome
• odontogenic keratocysts (epithelial jawline
  cysts)
• CNS calcifications (dura), mental retardation

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Basal Cell Carcinoma - Syndromes

• Bazex Syndrome
• AD
• Adolescence
• Multiple facial BCC
• Ice pick marks
• Hair abnormalities
• Foregut Neoplasms

• Possible responsiveness to Retinoic acid.

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Basal Cell Carcinoma - Syndromes

• Rombo Syndrome
• Autosomal Dominant
• Manifestation gt35 y
• Atrophoderma Vermiculatum
• Milia
• Peri follicualr pitting
• Scarring alopecia
• Peripheral vasodilation and cyanosis

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Other Associated Syndromes

• Xeroderma pigmentosum
• Incomplete sex-linked recessive
• Deficiency of endonuclease
• Childhood onset
• Extreme sun sensitivity
• BCC,SCC,Melanoma

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Other Associated Syndromes

• Albinism
• Genetic abnormality of the pigment system.

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Other Associated Syndromes

• Nevus Sebaceous of Jadassohn
• Usually sporadic
• Solitary patch/plaque
• Scalp
• Yellow-brown
• Present at birth/early childhood

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Basal Cell Carcinoma - Histopathology

• Resemble normal basal cells
• Hyperchromatic nuclei, scant cytoplasm
• Clustered separate from stroma
• Peripheral palisading
• Desmoplastic reaction
• Nests or in continuity

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Squamous Cell Carcinoma
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Squamous Cell Carcinoma

• Originates from spindle cell layer
• Older men sun exposed skin
• Sharply defined, erythematous plaque
• Elevated border

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Squamous Cell Carcinoma

• Painless firm nodule, scaling and horn formation
• Verrucous variant - fungating, slow growing,
  deeply invasive, less metastasis

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Squamous Cell Carcinoma

• Etiologic Factors
• Sun exposure
• Chronic ulceration (osteomyelitis, burn wounds)
• Cytotoxic agents, immunosuppressives
• Discoid Lupus
• Hydradenitis suppurativa
• Smoking, tobacco and Betel nut chewing

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Squamous Cell Carcinoma

• Histopathology
• Atypical cells replacing dermis
• Pleomorphic, multiple mitotic figures
• Migration through basement membrane
• Horn pearls
• Graded from well to poorly differentiated

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Squamous Cell Carcinoma Precursor Lesions

• Actinic (Solar) Keratosis
• Rough, scaly
• Erythematous plaques
• Forehead, nose, cheeks, pinna
• Multiple
• 25 Regress
• 11000 convert per year

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Squamous Cell Carcinoma Precursor Lesions

• Bowens Disease
• Older men
• Carcinoma in situ of skin or mucous membranes
• Mostly solitary
• Sharply defined.
• Dull scaly plaque
• Indolent history

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Squamous Cell Carcinoma Precursor Lesions

• Keratoacnathoma
• Rapid initial growth
• Latent period
• Fleshy, elevated, nodular
• Possible regression
• Grossly and microscopically resemble SCC
• Excision recommended

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Squamous Cell Carcinoma Precursor Lesions

• Leukoplakia
• Oral, vulvar, vaginal mucosa
• Smoking history
• Ill fitting dentures
• Elevated, sharply defined, patchy keratinization

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BCC and SCC- Approach to Treatment

• Surgical Excision
• Simple, versatile, fast
• Elliptical excision and primary closure
  applicable to 80 of BCC,SCC
• Large questionable lesions - biopsy
• ? - Delayed closure (awaiting pathology)
• Skin grafts, composite grafts, local flaps.
• Optimal surgical margin unknown

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Planning Margins for Primary excision BCC
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BCC and SCC- Approach to Treatment

• Mohs (Micrographic) Surgery
• Frederic Mohs, 1941
• Frozen Section
• Examine margins in three dimensions
• Medial canthus, alar regions

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BCC and SCC- Approach to Treatment

• Laser Excision
• CO2 laser
• Focused mode -coagulate and excise tissue
• Unfocused mode - vaporize small tumours.
• May hinder microscopic evaluation
• May damage the recipient bed for a graft.

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BCC and SCC- Approach to Treatment

• Non-Operative
• Radiation for BCC (4000-6000 cGy, 10-30
  fractions)
• older infirm patients
• difficult areas
• Complications dry eye, lacrimal duct scarring,
  skin necrosis
• Draw backs - no margins, multiple visits.

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BCC and SCC- Approach to Treatment

• Non -Operative
• Chemotherapy (5FU)
• hydrophilic base 5-20 concentration
• applied at night and covered
• 4-12 weeks
• Diffuse,Superficial Lesions, 5-20 mm.
• Heals over 1-2 months

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BCC and SCC- Approach to Treatment

• Non-Operative
• Isotretinoin
• in vivo antineoplastic effects, promoting
  cellular differentiation
• topical form only
• Interferon alpha
• nonspecific activation of macrophages and Natural
  Killer Cells.

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BCC and SCC- Approach to Treatment

• Non Operative
• Photo therapy
• Inactive agent administered
• Accumulates in tissue of interest
• Activated by LASER light.
• Cryosurgery
• Small nodular ulcerative, well-defined
• 5-15mm, wound contraction acceptable
• Liquid N2 (-195.6 C) used to reach intracellular
  temp of -40 C.

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BCC and SCC- Outcomes

• Risk Factors for Recurrence
• Long Duration
• High-risk area
• Large size
• Aggressive subtype
• Neglected
• Recurrent
• Radiation exposure

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BCC and SCC- Outcomes

• Acceptable goal
• Surgical excision
• Evaluation of margins
• Re-excision of involved margins
• Yields 95 cure rate for primary tumours

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BCC and SCC- Outcomes

• The Positive Margin
• Microscopic re-excise wound scar
• Observe Recurrence typically within 2 years,
  30.
• ? increased risk for deep and lateral margins
• Grossly Recurrent tumour re-excise wide margins.
  Poor cosmetic result

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Primary Skin Malignancies

• Common
• Increasing incidence
• High cure rates
• High patient-surgeon satisfaction.
• Can be a technical challenge
• Still many unanswered questions ...

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The Cases