What is the recommended treatment approach for a patient with a conjunctival nevus?

Conjunctival Nevus Management

Observation with serial photography is the recommended approach for conjunctival nevi, as these benign lesions have an extremely low risk of malignant transformation (approximately 0.2-1%), and surgical excision is reserved for specific clinical indications rather than routine management. 1, 2

Initial Assessment and Diagnosis

Clinical examination should focus on specific features that distinguish benign nevi from malignant lesions:

• Perform slit-lamp biomicroscopy to evaluate location, depth, elevation, and associated findings 3
• Look for characteristic features of benign nevi: well-circumscribed borders, variable pigmentation (amelanotic to dark), intrinsic clear cysts (present in 78% of cases), and intrinsic blood vessels 1, 2
• Document the lesion with serial photography at baseline and follow-up visits 1, 4

Warning signs requiring urgent evaluation include: enlargement of the lesion, development of new blood vessels, thickening, ulceration, or recurrence in the same location, especially in elderly patients 3

Management Strategy

Observation Protocol (Primary Approach)

Most conjunctival nevi should be managed conservatively with observation:

• Schedule routine follow-up with photo documentation to monitor for changes 1, 4
• The incidence of documented tumor growth is only 4%, making routine excision unnecessary 4
• Malignant transformation is exceedingly rare, occurring in approximately 1 in 32 cases over 23 years of observation in one large series 2

Indications for Surgical Excision

Excisional biopsy with cryotherapy is indicated in specific circumstances:

• Suspicious features suggesting possible malignancy: documented growth, change in pigmentation, development of prominent feeder vessels, or atypical biomicroscopic features 3, 4
• Patient-driven factors: cosmetic concerns (12% of excisions), ocular surface irritation (25% of excisions), or patient anxiety about cancer (45% of excisions) 4
• Large or giant nevi (≥10 mm diameter): these represent 5% of conjunctival nevi and may warrant excision, though they still rarely transform to melanoma 2

Surgical Technique When Indicated

When excision is performed, the procedure should include:

• Wide excisional biopsy with cryotherapy to the surgical margins 2
• For large lesions involving multiple quadrants or requiring extensive reconstruction, amniotic membrane transplantation provides effective ocular surface reconstruction 5, 2
• Amniotic membrane grafting was used in 13% of giant nevus excisions with good outcomes 2

Post-excision outcomes:

• Nevus recurrence occurs in approximately 17% of cases after excision 2
• Other complications include pseudopterygium (4%), dry eye (4%), and blepharoptosis (4%) 2

Clinical Factors Associated with Excision

Statistical predictors that increase likelihood of surgical intervention include:

• Older patient age at presentation 4
• Larger basal tumor diameter 4
• Presence of prominent feeder vessels and intrinsic vasculature 4
• Corneal involvement 4
• Location on bulbar conjunctiva (97% of giant nevi) 2

Special Considerations

Patients on immunomodulatory medications require heightened surveillance:

• TYK2 inhibitors (such as deucravacitinib) may theoretically increase risk of malignant transformation through disruption of interferon-alpha, IL-12, and IL-23 signaling 6
• One case report documented rapid transformation of a stable nevus to melanoma within 6 months of starting deucravacitinib therapy 6
• Consider more frequent monitoring intervals for patients on JAK-STAT inhibitors or other immunosuppressive therapies 6

Biopsy is the gold standard when diagnosis is uncertain:

• Consider biopsy for atypical features, recurrent lesions in the same location, or elderly patients with history of multiple excisions 3
• Anterior segment optical coherence tomography can highlight subclinical cysts, whose presence supports the diagnosis of nevus over melanoma 1