Ocular Surface Squamous Neoplasia in a Living-Related Conjunctival Limbal Allograft.

To report a single case of ocular surface squamous neoplasia (OSSN) that occurred in a living-related conjunctival limbal allograft (lr-CLAL).Case report and literature review.A 70-year-old white man developed OSSN in a histocompatible identical lr-CLAL over 3 years after the surgical procedure. Incisional biopsy was performed, and topical interferon alpha-2b was initiated. Pathology results confirmed carcinoma in situ. After modest results with topical interferon alpha-2b, the patient was treated with excisional biopsy with mitomycin-C (0.04 mg/mL) and cryotherapy. Simultaneously, the lr-CLAL was replaced with a keratolimbal allograft of a deceased donor. The patient maintained 20/25 best-corrected visual acuity at last follow-up.We present an unusual case of primary OSSN in a recipient of an lr-CLAL that was clinically confined to the borders of the graft.