• The second most common skin cancer, ranking
behind basal cell carcinoma (4:1).
• 20% of cutaneous malignancies.
• Generally occurs in mid to late life (usually
after age 40).
• Most commonly affects areas of sun exposure.
• Men are affected more often than women.
• A number of variables must be considered
when evaluating a squamous cell carcinoma.
• They relate to the lesion’s ability to recur
locally and to metastasize:
3. Depth of invasion.
4. Histologic grade.
• The central zone of the face is considered a high
risk area for subclinical extension because of its
anatomy; lesions located in this area are
therefore at high risk for local recurrence.
• Lesions of the temple, dorsum of the hand, lips,
scalp, and penis are associated with a high risk of
metastatic disease. Patients with lesions in these
areas must be carefully examined for evidence of
• The larger the lesion, the greater the chance
for local recurrence. As a consequence,
excision margins are selected according to
• A 4- to 5-mm margin for lesions <2cm in
diameter and a 6- to 9-mm margin for lesions
>2cm in diameter have been recommended.
Depth of invasion and histologic grade
• Invasion into the deep dermis or subcutaneous
tissue and a Broder’s grade 2 or higher are
associated with higher recurrence rates.
• Squamous cell cancers demonstrate a propensity
to invade along perineural planes.
• The immunosuppressed or immunocompromised
patient has an increased risk for local recurrence
or metastasis (typically to regional lymph nodes).
Verrucous squamous cell cancer
• An exophytic wart-like appearance.
• Often arises on the foot or glans penis and
anal canal (giant condyloma of Buschke-
• Histologically, there is no invasion of the
• Squamous cell carcinomas are generally divided into
spindle cell and acantholytic types.
• Spindle cell tumors may appear similar to malignant
melanoma or superficial malignant fibrocytomas.
• Immunohistologic staining can help make this
differentiation. Squamous cell cancers are positive for
cytokeratin and negative for S-100; melanomas are S-
100-positive and cytokeratin-negative.
• Acantholytic-type squamous cell cancers usually arise
from acantholytic solar keratoses.
• Cumulative lifetime exposure to sunlight
Ultraviolet B radiation (290–320mm).
• Whites more than Blacks.
• Scrotal tumors in chimney sweeps (soot is the
• Chronic arsenic exposure.
• Exposure to radiation.
• Compromised immunity.
• Human papilloma virus (HPV) exposure (16 and
• Thermal injury.
• Chronic ulceration.
• Sinus tracts.
• Hidradenitis suppurativa.
• Chronic cutaneous lupus erythematosus.
• Genetic predisposition (xeroderma pigmentosum,
epidermal dysplasia, and recessive dystrophic
epidermolysis bullosa and oculocutaneous
• Alcohol and tobacco use.
• Wide excision: 4–5 mm margins for lesions <2cm in diameter and
6–9mm for larger lesions.
• Tumors at high risk for local recurrence and metastases are those
>1–2cm in diameter that have invaded the mid-dermis or deeper.
• Those involving cartilage and bone are extremely high risk.
• Squamous cell carcinoma of the lip, ear, temple, and genitalia and
lesions associated with the preexisting conditions previously
discussed are also high risk.
• For these high risk lesions, excision with a frozen section margin
check should be used to assess the adequacy of excision.
Superficial ablative techniques
• Squamous cell carcinoma in situ (Bowen’s
• Lesions that invade no deeper than the
N.B. Tumors that are indurated and have
undermined the skin laterally and those with
associated local pain may be deeply invasive and
should be treated by excision.
1-Curettage and electrodesiccation
• Superficial squamous cell cancers.
• Should not be used for lesions with aggressive
histology, large size, or high risk anatomic
location (central face).
• First, curettage is performed by paring down
the lesion to normal tissue.
• Then electrodesiccation is used to destroy
potential tumor nests at the base.
• Freezes tissue to -195.5°C with liquid nitrogen.
• Can be used for small lesions (<2cm) on the
eyelid, ear, chest, back, or tip of the nose.
• Also used for recurrent tumors with definable
• Should not be used for eyelid free margins,
the vermilion border of the lip, ala nasi, scalp,
and tumors >3cm.
• Cure rates approach 92%.
• Of particular value in the central face, ear, and forehead,
where excisional therapy is potentially deforming.
• Has the advantage of treating a wide region around the
tumor with excellent local control and good cosmetic
• Prior to initiating therapy, a biopsy should be obtained for
both histologic confirmation and evaluation of tumor
• Most tumors are treated with a dose of 4000–6000 cGy
to the superficial skin.
• The dose is usually divided over 3–4 weeks to prevent
• Short term, the most troublesome sequelae after
irradiation is “burn” to the area.
• Long-term sequelae include destruction of hair follicles
and sweat glands, radiation dermatitis leading to
changes in skin pigmentation (hyper- or
hypopigmentation), and the development of radiation-
induced precancerous lesions.
• A malignancy of basaloid epithelial cells and is
the most common cancer, outnumbering
cutaneous squamous cell cancer 4 : 1.
• Most often affects light-skinned people, and
rarely affects those with dark skin.
• Develops mainly on sun-exposed areas, the
incidence varying directly with increasing
accumulated sun exposure and inversely with
increasing skin pigmentation.
• Several distinctive clinical subtypes that correlate
with histology and biologic potential.
• In addition, these subtypes affect treatment
• Histologic subtypes include:
1. Nodular basal cell cancer (most common)
Nodular basal cell cancer
• An elevated papule with overlying telangiectasia.
• It can become ulcerated as it enlarges, giving the
appearance of having been nibbled at, leading to its
name “rodent ulcer.”
• Pigmented basal cell cancer is a variant of nodular
basal cell cancer that, because of its dark pigment,
must be differentiated from melanoma.
• This type often occurs in dark-skinned individuals.
Morpheaform or sclerosing basal cell cancers
• Also known as fibrosing or desmoplastic.
• A flat, scar-like appearance.
• Some demonstrate endophytic growth leading to a
true tumor margin that is larger than the visible margin
(should be palpated carefully to assess the true extent
of tissue induration).
• This biologic feature leads to a higher recurrence rate
and makes it considered aggressive.
Superficial basal cell cancers
• Tend to appear on the trunk and extremities.
• They appear as erythematous patches, some
have an overlying patchy scale-like or
• They are the most common type of basal cell
cancer, seen with chronic arsenism and in
• The margin of excision for basal cell cancers
<1cm in diameter should be 4–5mm wide.
• The margin should be increased up to 9 mm
for aggressive growth pattern basal cell cancer
and those >1cm in diameter.
• Margin checks at the time of excision are
mandatory for optimizing results.
Mohs’ micrographic surgery (MMS)
• Described in 1941 by Frederick Mohs.
• Its main advantages are high cure rates and
minimal tissue loss.
• Its ability to optimize tissue preservation is
important in areas where maintaining
function and cosmetic appearance is difficult,
such as the nose, eyelids, lips, ears, digits, and
• Cure rates of 96% and a favorable cosmetic outcome
for small lesions of the central face including the
eyelids, nose, and lips.
• Radiation dose varies between 100 and 300kV per day
and is given according to several fractionation
• Typically, 15–17 fractions are given for tumors <2cm in
diameter, increased to 20–22 fractions for tumors
>2cm in diameter, and increased to 30–33 fractions for
larger lesions involving cartilage.