Squamous Cell Carcinoma (Eyelid)

Squamous cell carcinoma of the eyelid accounts for about 5 to 10 percent of eyelid malignancies, and is more aggressive than basal cell carcinoma.

• Lower lid and lid margin are commonest sites.
• Risk factors: chronic ultraviolet exposure, actinic keratosis, immunosuppression (transplant recipients have up to 65 to 250 times the risk), xeroderma pigmentosum, previous radiation, HPV, and chronic inflammatory scars.
• Metastasis to preauricular and submandibular nodes in about 1 to 2 percent of eyelid lesions (higher for large or perineural tumours), and perineural spread along the trigeminal or facial nerve.

• Firm, indurated, scaly or ulcerated nodule or plaque with hyperkeratosis, irregular margins, and no pearly border.
• Rapid growth, bleeding, crusting.
• Loss of lashes, lid margin distortion, and sometimes a cutaneous horn.
• Perineural invasion: pain, numbness, paraesthesia of the forehead or cheek.
• Orbital invasion: proptosis, ophthalmoplegia.
• Premalignant lesions: actinic keratosis; in situ disease (Bowen disease) appears as a red, scaly, well demarcated plaque.

• Incisional or excisional biopsy for histology (grade, depth, perineural invasion).
• MRI with gadolinium for perineural spread (thickened enhancing nerves, foraminal widening); CT for bony invasion.
• Palpate regional nodes; ultrasound of parotid and cervical nodes, with fine needle aspiration of suspicious nodes. CT chest in high risk disease.
• High risk features: thickness over 6 mm, poorly differentiated histology, perineural invasion, immunosuppression, recurrent disease, lesion over 2 cm.

• Wide excision with margin control: Mohs surgery or excision with frozen sections, 4 to 6 mm margins. Reconstruct after clear margins with direct closure, Tenzel flap, Hughes tarsoconjunctival flap, Mustardé cheek rotation, forehead flap or full thickness skin graft, rebuilding both anterior and posterior lamellae.
• Sentinel node biopsy or neck dissection (parotidectomy and selective neck dissection) for nodal disease.
• Adjuvant radiotherapy for perineural invasion, positive margins, nodal disease: 60 to 66 Gy in 30 to 33 fractions.
• Advanced or metastatic disease: cemiplimab 350 mg intravenously every 3 weeks (response rate about 45 to 50 percent), or pembrolizumab 200 mg every 3 weeks. Cisplatin based chemotherapy is an alternative; cetuximab for selected patients.
• Orbital exenteration for extensive orbital involvement.
• Immunosuppressed patients: reduce immunosuppression where possible; consider switching to sirolimus or everolimus.
• Treat actinic keratoses (topical 5-fluorouracil 5 percent twice daily for 2 to 4 weeks, cryotherapy).
• Follow up every 3 months for 2 years, every 6 months to 5 years, with nodal examination.