Squamous Cell Carcinoma (SCC)

1. Introduction:

Squamous cell carcinoma (SCC) is a type of skin cancer that originates from the squamous cells of the skin and mucous membranes. SCC differs from basal cell carcinoma in its ability to invade and metastasize distantly.

2. Clinical Presentation:

History:

• SCC often arises from precancerous lesions such as leukoplakia, actinic keratosis, scars, dermatitis, etc.

Clinical manifestations:

• Papule/ firm plaque: Elevated, firm, pale pink in color.
• Ulceration, bleeding, cracking, brown-black crust.
• Rapid progression, distant metastasis.

3. Special Types of SCC:

SCC around the mouth:

• Commonly found on the lower lip.
• Often associated with a history of actinic cheilitis, leukoplakia in smokers and betel nut chewers.
• Ask about smoking and betel nut chewing history.

SCC around the nails:

• Can be mistaken for warts.

In situ SCC:

• Confined to the epidermis, not yet through the basement membrane.
• Slow progression.

Bowen’s disease:

• A form of in situ SCC on the male genital mucosa.

Keratoacanthoma:

• A rare form of SCC, commonly seen in the elderly.

4. Diagnosis:

• Biopsy: The definitive diagnostic method.
• Cytology: May be used as a supportive diagnosis.

5. Differential Diagnosis:

• BCC (Basal Cell Carcinoma): SCC is usually paler pink than BCC and has a higher risk of distant metastasis.
• Cutaneous tuberculosis: Often presents with inflammation and deeper ulceration than SCC.
• Deep fungal infection: Usually presents with more inflammation, scales, and possible secondary infection than SCC.
• Mycossis fungoides: Typically presents with inflammation, ulceration, crusting, and possible secondary infection.

6. Risk Factors:

• Sun exposure: The leading risk factor.
• Smoking: Increases the risk of SCC around the mouth.
• Betel nut chewing: Increases the risk of SCC around the mouth.
• Exposure to harmful chemicals: Such as arsenic, petroleum, etc.
• Weakened immune system: Due to medical conditions, immunosuppressant drugs, etc.
• Precancerous skin lesions: Such as leukoplakia, actinic keratosis, etc.
• Genetic disorders: Such as xeroderma pigmentosum, etc.

7. Treatment:

Surgery:

• Excision: Removal of the lesion and surrounding area with a 1 cm margin, deep into the subcutaneous tissue.
• Mohs surgery: A micrographic surgical technique that helps remove all cancer cells while preserving healthy tissue to the maximum extent possible.

• Lymph node dissection: Indicated if the cancer is larger than 2 cm or if clinically palpable lymph nodes are present.
• Radiation therapy: Used if surgery is not feasible or if there is lymph node metastasis.
• Photodynamic therapy: Uses light-sensitive drugs to kill cancer cells.
• Chemotherapy: Rarely used.

8. Follow-up:

• Regular follow-up: After treatment, regular follow-up is needed to detect early metastasis.
• No metastasis: 1 year/visit.
• With metastasis: 3-6 months/visit.

9. Prevention:

• Avoid sun exposure: Use sunscreen, hats, sunglasses.
• Quit smoking: Helps reduce the risk of SCC around the mouth.
• Limit betel nut chewing: Helps reduce the risk of SCC around the mouth.
• HPV vaccination: Helps reduce the risk of SCC in the genital area.

10. Note:

• SCC can metastasize distantly and be fatal if not treated promptly.
• Regular dermatological examinations are necessary for skin cancer screening.
• Early diagnosis and treatment are key to successful treatment.

11. Additional information:

• SCC is more common in older adults, men, and fair-skinned individuals.
• SCC can appear anywhere on the body but is more common in areas exposed to sunlight, such as the face, neck, arms, and legs.
• SCC is usually pale pink or red and may have scales, ulceration, or bleeding.
• If you suspect you may have SCC, see a dermatologist immediately.

12. Note:

• This article is for informational purposes only and does not substitute for the advice of a medical professional.
• For an accurate diagnosis and treatment, you should consult with a specialist doctor.