CONJUNCTIVAL CARCINOMA IN SITU MIMICKING A PTERYGIUM: A CASE REPORT

Introduction: Ocular surface squamous neoplasia (OSSN) encompasses a spectrum of epithelial lesions ranging from mild dysplasia to invasive squamous cell carcinoma, and may closely mimic benign conditions such as pterygium. Clinical diagnosis is unreliable, and histopathology remains the gold standard.
Case presentation: A 65-year-old man with no medical history presented with a foreign-body sensation in the right eye. Slit-lamp examination revealed a 6-mm reddish, elevated, poorly demarcated, slightly nodular perilimbal lesion of the nasal bulbar conjunctiva, extending slightly onto the cornea, with surface microvessels and a superonasal feeder vessel. Best-corrected visual acuity was 9/10 in both eyes, and intraocular pressure and fundus examination were normal. After a short course of topical anti-inflammatory treatment and artificial tears, the lesion was excised with intraoperative application of 0.02% mitomycin C. Histopathology showed conjunctival carcinoma in situ with clear surgical margins. Adjuvant topical mitomycin C 0.02% was administered (two 15-day cycles separated by a two-week interval). The course was favorable, with no recurrence at follow-up.
Conclusion: Any atypical, vascularized or poorly demarcated conjunctival growth, even when resembling a pterygium, should be excised and systematically submitted to histopathological examination. Prolonged follow-up is essential because late recurrences may occur.