Squamous cell carcinoma and basal cell carcinoma are the two most common types of non-melanoma skin cancer. Squamous cell carcinoma occurs more often in sun-exposed areas and affects men more than women. Larger lesions, deeper invasion and higher grades are associated with greater recurrence risk. Treatment options include excision, cryotherapy and radiation therapy. Basal cell carcinoma is more common and occurs predominantly in light-skinned individuals on sun-exposed areas. The nodular type is most common. Treatment involves wide local excision, Mohs surgery, or radiation therapy depending on size and location.

1. Non-melanoma Skin Cancers
Ihab Samy
Lecturer of surgical oncology
NCI – Cairo University

2. Squamous Cell Cancer

3. Epidemiology
• 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.

4. • 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:
1. Location.
2. Size.
3. Depth of invasion.
4. Histologic grade.

5. Location
• 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
regional lymphadenopathy.

6. Size
• The larger the lesion, the greater the chance
for local recurrence. As a consequence,
excision margins are selected according to
tumor size.
• 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.

7. 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).

8. Verrucous squamous cell cancer
• An exophytic wart-like appearance.
• Often arises on the foot or glans penis and
anal canal (giant condyloma of Buschke-
Lowenstein).
• Histologically, there is no invasion of the
dermis.

9. • 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.

10. Risk Factors
• Cumulative lifetime exposure to sunlight 
Ultraviolet B radiation (290–320mm).
• Whites more than Blacks.
• Scrotal tumors in chimney sweeps (soot is the
causative agent).
• Chronic arsenic exposure.
• Exposure to radiation.
• Compromised immunity.

11. • Human papilloma virus (HPV) exposure (16 and
18).
• 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
albinism).
• Alcohol and tobacco use.

12. Treatment
• Excisional therapies
• Superficial ablative therapies.
• Radiation therapy.

13. Excision
• 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.

14. Superficial ablative techniques
• Squamous cell carcinoma in situ (Bowen’s
disease).
• Lesions that invade no deeper than the
superficial dermis.
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.

15. 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.

18. 2-Cryotherapy
• 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
margins.
• Should not be used for eyelid free margins,
the vermilion border of the lip, ala nasi, scalp,
and tumors >3cm.

20. Radiation therapy
• 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
outcome.
• Prior to initiating therapy, a biopsy should be obtained for
both histologic confirmation and evaluation of tumor
thickness.

21. • 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
complications.
• 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.

22. BASAL CELL CANCER

23. • 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.

25. Histology
• Several distinctive clinical subtypes that correlate
with histology and biologic potential.
• In addition, these subtypes affect treatment
choices.
• Histologic subtypes include:
1. Nodular basal cell cancer (most common)
2. Morpheaform.
3. Superficial.
4. Fibroepitheliomatous.
5. Infundibulocystic.

27. 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.

29. 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.

32. 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
pigmented appearance.
• They are the most common type of basal cell
cancer, seen with chronic arsenism and in
radiation fields.

34. Treatment
• Wide excision (Mohs’ microsurgical therapy).
• Curettage and electrodesiccation
• Cryotherapy.
• Radiation therapy.

35. Surgical excision
• 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.

36. 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
genitalia.

38. Irradiation
• 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
schedules.
• 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.

39. Cases

40. 1st Case

44. 2nd Case

48. 3rd Case

51. Thank you