Basal Cell Carcinoma (Eyelid)

Basal cell carcinoma is the commonest malignant eyelid tumour (about 90 percent of eyelid malignancies).

• Lower lid about 50 to 60 percent, medial canthus 25 to 30 percent, upper lid about 15 percent, lateral canthus 5 percent.
• Risk factors: chronic ultraviolet exposure, fair skin (Fitzpatrick I and II), age over 50, immunosuppression, xeroderma pigmentosum, and Gorlin syndrome (PTCH1 mutation) with multiple early lesions.
• Locally invasive and almost never metastatic (less than 0.1 percent); morbidity comes from orbital invasion, especially from the medial canthus.

• Nodular (about 80 percent): pearly, translucent nodule with rolled edges and telangiectasia, central ulceration ("rodent ulcer").
• Morphoeic (sclerosing): flat, indurated, ill defined plaque with loss of lashes and normal architecture; subclinical spread is wide.
• Pigmented and superficial variants occur.
• Loss of eyelashes (madarosis), margin distortion, lid notching, and chronic unilateral "blepharitis" that does not respond to treatment.
• Signs of orbital invasion: proptosis, restricted motility, diplopia, fixed mass.

• Clinical suspicion with dermoscopy; confirm with biopsy: incisional (punch or wedge) for large or morphoeic lesions, excisional for small ones. Histology: basaloid nests with peripheral palisading and retraction clefts.
• High risk features: medial canthus site, morphoeic or infiltrative subtype, perineural invasion, recurrent tumour, size over 2 cm.
• Imaging: CT or MRI orbits (contrast, fat suppression) if orbital or perineural invasion suspected.
• Examine regional nodes. Systemic staging is not routine.

• Surgical excision is first line. Mohs micrographic surgery gives the lowest recurrence (about 1 to 5 percent) and best tissue preservation; the alternative is wide local excision with frozen section control of margins (3 to 4 mm clinical margin for nodular, 4 to 5 mm or more for morphoeic).
• Reconstruct after clear margins confirmed: direct closure, lateral cantholysis, Tenzel flap, Hughes flap, Mustardé cheek rotation, forehead flap, full thickness skin graft, or tarsoconjunctival graft, depending on the defect and lid layers involved. Rebuild both anterior and posterior lamellae.
• Non-surgical options for non-resectable disease or poor surgical candidates:
  • Vismodegib 150 mg orally once daily, or sonidegib 200 mg orally once daily (hedgehog pathway inhibitors): response in about 45 to 60 percent of locally advanced tumours. Adverse effects: muscle cramps, alopecia, taste loss, weight loss. Teratogenic; contraception required.
  • Radiotherapy, for example 50 to 55 Gy in 20 fractions, for older patients and non-operable lesions.
  • Topical imiquimod 5 percent five times a week for 6 weeks is reserved for superficial lesions away from the lid margin.
• Orbital exenteration for extensive orbital invasion unresponsive to other therapy.
• Follow up every 6 months for 5 years and annually thereafter for new lesions; sun protection counselling.