Cutaneous SCC

Question 1

What are the layers of the epidermis from superficial to deep?

Answer 1

● Stratum corneum (cornified layer)
● Stratum granulosum (granular layer)
● Stratum spinosum (spinous layer)
● Stratum germinativum (basal layer)
The dermis is immediately deep to this.

Question 2

Name the four cell types of the epidermis.

Answer 2

● Keratinocytes (80%)
● Merkel cells (mechanoreceptors)
● Langerhans cells (antigen processing and presenting cells
● Melanocytes (pigmented dendritic cells)

Question 3

What is the “H-zone” of the head and neck?

Answer 3

This area extends vertically from the angle of the mandible
through the ear and preauricular region to the temple and
is connected horizontally through the periorbital skin, nasal
skin, and upper lip.

Question 4

Which skin cancer type is most common on the

lower lip?

Answer 4

Squamous cell carcinoma

Question 5

What risk factors are associated with lymphatic metastasis of cutaneous squamous cell carcinoma?

Answer 5

● Area > 20 mm (less in the H-zone)
● Recurrent tumors
● Site of prior radiation or scar
● Rapidly growing tumor
● Perineural invasion
● Poorly differentiated tumors, high-grade tumors
● Depth > 5 mm or subcutaneous fat
● Lymphovascular invasion
● Immunosuppression

Question 6

Metastasis from cutaneous head and neck squamous cell carcinoma most commonly occurs in which lymphatics?

Answer 6

About 75% of cutaneous lymphatic metastases occur in the

parotid bed; 40% occur in level II.

Question 7

What are risk factors for cutaneous squamous cell

carcinoma of the head and neck?

Answer 7

● Ultraviolet radiation is the number 1 risk factor
● Light skin pigmentation
● Ionizing radiation
● Immunosuppression
● Exposure to coal tar, asphalt, and arsenic consumption
● Xeroderma pigmentosa, basal cell nevus syndrome
● Tendency to burn or freckle (rather than tan)
● Male sex

Question 8

Describe the Fitzpatrick scale.

Answer 8

Classification schema for the color of skin. Associated with decreasing risk of cutaneous malignancy:
● Type I: Pale white, blond, or red hair; blue eyes; always
burns, never tans; freckles
● Type II: White, fair, blond or red hair; blue, green, or hazel
eyes; tans minimally, often burns
● Type III: Fair skin; any hair and eye color; tans evenly,
sometimes burns.
● Type IV: Mediterranean skin, rarely burns, tans easily
● Type V: Dark brown skin, rarely burns, tans easily
● Type VI: Dark brown to black, never burns, tans very easily

Question 9

What are the risk factors for development of solar
keratosis, how many of these eventually undergo
malignant transformation, and what percentage of
squamous cell carcinomas can be traced to actinic
keratosis?

Answer 9

Sun exposure is the most important risk factor, but immune suppression is also important (immunsuppressed individuals are 250 times more likely to develop solar keratoses). Fewer than 1/1,000 solar keratoses will go on to become squamous cell carcinoma; 60% of squamous cell
carcinomas can be traced back to solar keratoses.

Question 10

What is Marjolin ulcer?

Answer 10

Marjolin ulcer is a term used to describe an ulcerative
squamous cell carcinoma at the site of prior trauma,
inflammation, or scarring such as radiation or a burn.

Question 11

What percentage of nonmelanoma cutaneous
malignancies are made up of squamous cell
carcinoma?

Answer 11

20%

Question 12

Which pathologic finding in squamous cell carcinoma is associated with the highest recurrence rate and regional metastasis?

Answer 12

Perineural invasion. This is associated with metastasis in

47% of patients.

Question 13

How many solar keratoses eventually undergo

malignant transformation?

Answer 13

Fewer than 1 in 1,000 solar keratoses will become

squamous cell carcinoma.

Question 14

What percentage of squamous cell carcinomas can

be traced to actinic keratosis?

Answer 14

60%

Question 15

Describe the clinical and pathological characteristics of Bowen disease.

Answer 15

Bowen disease is an intraepidermal squamous cell carcinoma

that manifests as an enlarging, well-demarcated erythema-
tous plaque with surface crusting. Histologically, it resembles

squamous cell carcinoma with atypical keratinocytes replac-
ing epidermis. It appears more commonly in women (70 to

85%) and in the sixth or seventh decades of life. It can appear
anywhere, but it is more common in the lower legs. The cause

has been traced to sun exposure, arsenic, immune suppression, and viral infection. Treatment is most often provided with cryotherapy, curettage, excision, laser, photodynamic
therapy and topical 5-fluorouracil (5-FU), with no treatment
showing a clear superior effect.

Question 16

What type of skin cancer is known for rapid
progression of a swelling, dome-shaped lesion that
eventually resolves by sloughing off and scarring?

Answer 16

Keratoacanthoma

Question 17

Your patient, a 67-year-old farmer, has a rapidly
expanding, symmetric, dome-shaped lesion on his
neck. The lesion is surrounded by smooth, inflamed
skin, but it has a central crater containing keratinous
debris. What is the most likely diagnosis?

Answer 17

Keratoacanthoma

Question 18

Describe the typical manifestation of a keratoacanthoma.

Answer 18

Keratoacanthomas are rapidly growing lesions that may

then slowly spontaneously involute after a plateau phase.

Question 19

Describe the typical manifestation of cutaneous

squamous cell carcinoma.

Answer 19

Cutaneous squamous cell carcinoma can present in a number
of ways: A thick, scaly patch, an ulcerated patch with rolled
borders, a nodular lesion, or scale with pigmentation

Question 20

What symptoms should be elicited in an history of
present illness for a patient with newly diagnosed
cutaneous squamous cell carcinoma?

Answer 20

Symptoms of advanced disease: numbness, pain, weakness
or other perineural symptoms; weight loss, bone pain,
shortness of breath to suggest distant disease; rapid
growth, bleeding, fixation, neck mass to suggest locally
advanced or aggressive disease

Question 21

What features of cutaneous squamous cell carcinoma merit radiologic workup?

Answer 21

● Locally advanced disease: Fixation, numbness, weakness,
pain or trismus, extensive lesions (> 2 cm), or perineural
or lymphovascular invasion
● Regionally advanced disease: Palpable lymphadenopathy,
intransit metastasis
● Distant metastasis risk: Axillary adenopathy, bone pain, shortness of breath, unexplained weight loss, unex-
plained neurologic symptoms
● High-risk patients: Recurrent lesions, immunosuppres-
sion, history of radiation

Question 22

What is the most appropriate biopsy technique for
deep ulcerated lesions of the skin of the head and
neck?

Answer 22

● Punch of incisional biopsy at the thickest portion of the
lesion
● Full-thickness biopsy should be attempted and should
involve the reticular dermis or subcutaneous fat when
possible.

Question 23

What features of head and neck nonmelanoma
skin cancer are associated with American Joint
Committee on Cancer (AJCC) T2 tumors?

Answer 23

Greater than 2 cm greatest dimension or
Two or more high-risk features:
● > 2-mm invasion
● Clark level ≥ IV
● Perineural invasion
● Primary site ear
● Primary site non-hairbearing lip
● Poorly or undifferentiated tumor
Note: Excludes cutaneous squamous cell carcinoma of the
eyelid

Question 24

What features of head and neck nonmelanoma
skin cancer are associated with T3 and T4 tumors
(AJCC seventh edition)?

Answer 24

● T3: Invasion of the maxilla, mandible, orbit, or temporal
bone
● T4: Perineural invasion of the skull base

Question 25

What are the high-risk features of head and neck

cutaneous squamous cell carcinoma?

Answer 25

Deep lesions (< 2 mm, Clark level IV)
● Perineural invasion
● H-zone lesions
● Recurrent lesions
Lesions arising in radiated fields or scar
● Size > 1.5 cm
● Poorly differentiated lesions
● Immunosuppression

Question 26

What locations of head and neck cutaneous
squamous cell carcinoma are more likely to exhibit
recurrence and why?

Answer 26

High-risk sites for recurrence include the so-called H-zone
along the preauricular and postauricular areas as well as across
the midface, including the nose. This has been attributed to
these sites being the location of embryologic fusion, affording
tumors planes that provide avenues for spread.

Question 27

True or False: Pathologic involvement of neck
nodes with metastatic cutaneous squamous cell
carcinoma is associated with worse survival in
patients who also have parotid metastasis.

Answer 27

True. Andruchow et al 2006

Question 28

What are appropriate margins for low-risk cutaneous squamous cell carcinoma?

Answer 28

4- to 6-mm clinical margins.

Question 29

Although not yet approved by the Food and Drug
Administration (FDA), imiquimod has shown some
promise of utility for the treatment of cutaneous
squamous cell carcinoma. What is the mechanism
of action for imiquimod?

Answer 29

Imiquimod is a local immune response modifier that

induces activity of interferon-α and other cytokines.

Question 30

Describe the technique for electrodessication and
curettage (EDC) used in cutaneous squamous cell
carcinoma and basal cell carcinoma.

Answer 30

In EDC, a curette is used to scrape tumor off down to the
dermis, following which an electrodessication is performed
to denature any cells along the surface. This is repeated
until a satisfactory depth of excision is reached.

Question 31

When is Mohs surgery indicated for cutaneous

squamous cell carcinoma of the head and neck?

Answer 31

● Anatomically or aesthetically sensitive areas where wide margins are not achievable (periorbital, nasal, periauricular and auricular, and perioral)
● Positive margins after wide local excision and potential
extension into an area fulfilling the first criteria

Question 32

When is radiation indicated for cutaneous squamous cell carcinoma?

Answer 32

● Nonoperative candidates (surgical risk or unresectable)
● Positive margins or incomplete excision
● Solitary node ≥ 3 cm or with extracapsular extension
● Multiple positive nodes
● Multiple recurrent disease despite appropriate treatment
● Perineural invasion of major (named ) nerve or extensive
perineural invasion
● T4 disease

Question 33

What is the appropriate treatment of keratoacanthoma?

Answer 33

● Wide local excision is preferred
● Intralesional methotrexate, steroids, and 5-FU can be
used for nonoperative cases.