Conjunctival melanoma masquerading as a benign conjunctival lesion: The importance of recognising change and appropriate safety-netting

Purpose: To describe a case of conjunctival melanoma presenting as a progressively enlarging pigmented conjunctival lesion and to highlight the importance of recognising suspicious clinical features, appropriate safety-netting, and timely referral to specialist ocular oncology services.

Methods: Retrospective observational case report based on review of clinical records and anterior segment slit lamp photographs. Oral informed consent was obtained from the patient. 

Results: A 69-year-old patient was referred to the cornea clinic with an enlarging right conjunctival lesion associated with pain, discharge, and blurred vision. The lesion had progressively increased in size over approximately 18 months. Four years earlier, the patient had been assessed for a small, raised conjunctival lesion at the same location and treated with topical corticosteroids before discharge. Past medical history included successfully treated testicular cancer at age 20.

Examination demonstrated an ill-defined pigmented temporal conjunctival lesion adjacent to the limbus, with a prominent feeder vessel, discharge, and tenderness. There was no anterior chamber inflammatory activity. Unaided visual acuity was 6/36 in the right eye, improving to 6/9 with pinhole, and 6/9 in the left eye.

Given the progressive enlargement, pigmentation, and prominent vascularity, an urgent referral was made to the ocular oncology service. Topical levofloxacin was commenced for the associated discharge while awaiting specialist assessment.

Following ocular oncology evaluation, conjunctival melanoma was diagnosed. The patient subsequently underwent surgical excision with adjunctive cryotherapy and graft reconstruction, followed by radiotherapy as part of definitive oncological management. Visual acuity subsequently improved to 6/6 in both eyes, with ongoing surveillance arranged locally and through the ocular oncology service. The patient later underwent proton beam therapy and continues to recover.

Conclusion: This case highlights the importance of maintaining a high index of suspicion when assessing conjunctival lesions, particularly those demonstrating progressive growth, pigmentation, prominent feeder vessels, or other atypical features. Symptoms suggestive of ocular surface inflammation should not preclude consideration of an underlying neoplastic process.

Previous treatment for a presumed benign or inflammatory lesion should not provide reassurance if subsequent growth or morphological change occurs. Careful documentation of lesion size, location, pigmentation, vascularity, and appearance is essential to facilitate detection of progression over time.

Robust safety-netting is particularly important when patients with apparently benign conjunctival lesions are discharged. Patients should be advised to seek prompt reassessment if lesions enlarge, change in appearance, or become symptomatic. Early recognition of suspicious change and timely referral to specialist ocular oncology services are essential for appropriate diagnosis and management.