Squamous Cell Carcinoma

Squamous cell carcinoma (SCC) can be classified as an eye cancer when it affects parts of the eye or its surrounding structures, though it is more accurately described as an ocular surface or ocular adnexal cancer, depending on its location.

Squamous cell carcinoma (SCC) is a common type of skin cancer that can affect the eye and surrounding tissues, especially in areas exposed to sunlight, such as the eyelids, conjunctiva, and cornea. It arises from the squamous epithelial cells that line the skin and mucous membranes and has the potential to be locally invasive and, in rare cases, metastasize to other parts of the body.

When SCC occurs in the ocular region - particularly the conjunctiva - it often appears as a reddish, elevated, or gelatinous growth, sometimes with surface keratin or vascularization. Risk factors include UV exposure, older age, immunosuppression, and human papillomavirus (HPV) infection.

Diagnosis is made through clinical examination, biopsy, and sometimes imaging to assess local invasion or spread. Treatment typically involves surgical excision with clear margins, cryotherapy, topical chemotherapy (such as mitomycin C), or radiation therapy, depending on the size and location of the tumor.

Although SCC has a relatively good prognosis with early treatment, recurrence is possible, and regular follow-up is important, especially for ocular surface involvement.

🧿 Squamous Cell Carcinoma (SCC) Fact Sheet

Cancer Type: Rare Eye Cancer (Epithelial Malignancy)
Primary Site: Conjunctiva, cornea, eyelid, limbus, or orbit
Subtype: Ocular Surface Squamous Neoplasia (OSSN), Cutaneous SCC of eyelid
Website Reference: OcularCancer.com

🔍 What is Squamous Cell Carcinoma?

Squamous Cell Carcinoma (SCC) is a malignant tumor arising from squamous epithelial cells. In the eye, it typically develops on the conjunctiva or cornea, and may extend to the eyelid, limbus, or orbit.

When it affects the ocular surface, it falls under the umbrella of Ocular Surface Squamous Neoplasia (OSSN) - a spectrum that includes dysplasia, carcinoma in situ, and invasive SCC.

📊 Key Facts:

Prevalence: Rare; OSSN accounts for ~5% of all ocular tumors
Most Common Site: Conjunctiva, especially at the limbus
Age of Onset: Typically affects adults aged 50+
Gender: More common in males
Geographic Risk: Higher prevalence in equatorial regions (UV exposure)
Laterality: Usually unilateral, localized but may invade orbit if untreated

🧬 Causes & Risk Factors:

Chronic UV-B radiation exposure (sunlight)
Fair skin, light eye color
HPV infection (especially types 16 & 18)
HIV/AIDS and other immunosuppressive conditions
Cigarette smoking
Chronic ocular inflammation or scarring
Xeroderma pigmentosum (genetic condition causing UV sensitivity)

👁️ Signs and Symptoms:

SCC often resembles benign growths and may go unnoticed early. Common signs include:

White, pink, or gelatinous mass on the conjunctiva
Leukoplakia (white plaque)
Feeder blood vessels leading to the lesion
Persistent redness, irritation, or foreign body sensation
Decreased or blurry vision if the cornea is involved
Eyelid mass or ulceration (in cutaneous SCC)
Bleeding, crusting, or loss of eyelash in advanced eyelid SCC

🩺 Diagnosis:

Clinical eye exam with slit-lamp and observation of lesion characteristics
High-resolution anterior segment imaging (HR-OCT)
Biopsy (excisional or incisional) with histopathologic confirmation
Immunohistochemistry to differentiate from other ocular malignancies
HPV testing if viral cause suspected
Imaging (MRI or CT) for deeper orbital or lymphatic invasion

⚙️ Types of Ocular SCC:

Conjunctival SCC (Invasive OSSN):
Most common; starts at limbus and can spread to orbit if untreated
Corneal SCC:
Less common; often an extension of conjunctival involvement
Eyelid SCC:
Cutaneous form; may ulcerate and mimic basal cell carcinoma
Orbital SCC:
Very rare; may result from local invasion

🧪 Treatment Options:

Treatment depends on the extent, location, and depth of invasion:

Surgical excision with wide margins
Cryotherapy to lesion edges and conjunctiva
Topical chemotherapy:
- Mitomycin C
- 5-Fluorouracil (5-FU)
- Interferon alpha-2b drops (less toxic alternative)
Radiation therapy:
For unresectable, recurrent, or orbital-invasive cases
Orbital exenteration:
In extensive cases with deep tissue invasion
Lymph node biopsy or dissection if metastasis is suspected

🎯 Prognosis:

Early-stage SCC has a high cure rate with surgical and medical treatment
Recurrence rate: ~10–30%, especially with incomplete excision
Metastasis: Rare but possible to regional lymph nodes, lungs, or brain
Orbital invasion significantly worsens prognosis

🔄 Follow-Up & Monitoring:

Frequent ophthalmic exams (every 3–6 months initially)
Monitoring for local recurrence or new lesions
Lymph node checks during follow-up visits
HIV testing in immunocompromised patients
Long-term follow-up required due to recurrence risk

❤️ Support & Resources:

Ocular oncologists and cornea specialists for diagnosis and management
Dermatology support for cutaneous SCC cases
HIV clinics or infectious disease specialists if immunosuppression is involved
Cancer support groups for mental and emotional support
Patient advocacy organizations for rare cancer care access

📌 Key Takeaways:

Ocular SCC is rare and potentially aggressive, especially if untreated
Early signs may mimic benign conditions like pinguecula or pterygium
Early biopsy and prompt treatment are key to preserving vision and preventing spread
Topical treatments can be effective for superficial lesions
Recurrence is possible; lifelong monitoring is recommended