Topic 5. Squamous Cell Carcinoma

7/28/2019 Topic 5. Squamous Cell Carcinoma

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Efi. Gelerstein 2011

Topic 5. Squamous cell carcinoma

Background

Malignant tumor derived from suprabasale epidermal keratinocytes( keratin) The 2nd most common form of skin cancer and accounts for 20% of cutaneous malignancies. Frequently arises on the sun-exposed skin of middle-aged and elderly individuals (as BCC) Inverse relationship b/w skin pigmentation and SCC incidence Carries a significant risk ofmetastasis M / F 2:1

Predisposing Factors

1. Age > 50 years2. Light skin; blonde / light brown hair; green, blue, or gray eyes3. Precursor lesions4. UV exposure5.

Ionizing radiation

6. Environmental carcinogens7. Immunosuppression8. Scars and underlying diseases9. HPV

10. Genodermatoses hereditary skin disorder, caused by a genetic mutation in a gene whose functionis important in maintaining the normal physiology of the skin

Pathophysiology

A malignant tumor of epidermal keratinocytes. May occur de novo (i.e., in the absence of a precursor lesion) Some arise from sun-induced precancerous lesions known as actinic keratoses (AKs) Capable of locally infiltrative growth, spread to regional lymph nodes, and distant metastasis, most

often to the lungs.

Mortality / Morbidity

Risk of metastasis 2-6% Perineural invasion 47% Lymph node metastasis is associated with significant morbidity Once lung metastasis occurs, the disease is currently incurable.

History

Slow-growing malignancy, but some lesions enlarge rapidly. Although most SCC patients are asymptomatic, symptoms such as bleeding, weeping, pain, or

tenderness may be noted, especially with larger tumors.

Numbness, tingling, or muscle weakness may reflect underlying perineural involvement, and thishistory finding is important to elicit because it adversely impacts prognosis.
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Clinical manifestations

1. Head, neck, dorsal hands2. Firm, flesh-colored keratotic papule or plaque3. Expanding tumor with necrotic ulcer4. Thick cutaneous horn5. verrucous6. Fixation to underlying tissue - progressive tumor invasion

Other clinical variants of SCC

1. Oral SCC2. Lower lip SCC3. Genital SCC4. Scar SCC5. Keratoacanthoma SCC6. Verrucous carcinoma: cauliflower-like appearance.

Physical:

SCC may manifest as a variety of primary morphologies with or without associated symptoms.

1. Squamous cell carcinoma in situ (SCCis): Involving the full thickness of the epidermis but without invasion into the dermis. Scaly pink patch to a thin keratotic papule or plaque (similar to an AK).

2. Typical squamous cell carcinoma: Raised, firm,pink-to-fleshcolored keratotic papule or plaque arising on sun-exposed skin. ~ 70% of all SCC occur on the head and neck, with additional 15% found on upper extremities. Surface changes: Scaling, ulceration, crusting Less common: pink cutaneous nodule without overlying surface changes.

3. Periungual squamous cell carcinoma: (verrucous carcinoma?) Mimics a verrucous and is frequently misdiagnosed as a wart prior to biopsy. Less commonly, lesions may resemble chronic paronychia with swelling, erythema, and

tenderness of the nail fold; onychodystrophy also may be noted.

4. Scar SCC (Marjolin ulcer): Appears at the site of a preexisting trauma, scar or ulcer. Diagnosis should be considered in any ulcer that fails to heal with standard therapy.

5. Perioral SCC (Oral + Lip): usually arises on the border of the lower lip. Manifests as a new papule, erosion, or focus of erythema/induration. Intraoral SCC typically manifests as white plaque (leukoplakia) reddish reticulation

(erythroplakia).


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6. Genital SCC (Anogenital): Manifest as a moist, red plaque on the glans penis. Associated symptoms include pain, pruritus, and intermittent bleeding.

Lymphadenopathy: With any invasive (not in situ) squamous cell carcinoma, regional lymph nodes

should be examined. Lymph node enlargement must be further evaluated by fine-needle aspiration (FNA)

or nodal biopsy

Histology

Keratinocytes disrupt the dermo-epidermal junction and proliferate irregularly into the dermis. Malignant cells usually retain the capacity to produce keratin

Treatment of SCC

Goal: cure of the tumor with the maximal preservation of function and cosmesis. Surgical approaches offer the most effective and efficient means for cure.

1. Standard excision with 5-10 mm safety zone2. Mohs micrographic surgery

Radiation therapy: considerations of function,cosmesis, and patient preference may indicate it.1. Total of 5,000-6,000 cGy in 250 cGy fractions

Patient education

Sun avoidance and protection. Monthly self-examination of all skin surfaces. With a history of invasive skin cancer, selfexamination of the lymph nodes. Organ transplant recipients: start education at transplantation. Xeroderma pigmentosum: start education at birth or diagnosis


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Topic 5. Squamous Cell Carcinoma

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