Periocular granulomatous inflammatory lesions mimicking conjunctival melanoma recurrence in the setting of systemic nivolumab treatment.

Purpose: Conjunctival melanoma is a rare neoplasm with high rates of recurrence and metastasis. Traditional management includes surgical excision and cryotherapy, followed by adjuvant therapy as needed. Immune checkpoint inhibitors, including nivolumab, are a targeted treatment option with improved survival rates. However, various immune-related adverse effects have been reported with these drugs. While systemic granulomatous inflammation is a documented systemic side effect, it has rarely been reported in the conjunctiva and ocular adnexa. Observation: A patient with a history of recurrent metastatic conjunctival melanoma presented with both a left sub-conjunctival and upper eyelid lesion after the commencement of treatment with nivolumab. The lesions were excised with a clinical suspicion for metastasis and consisted of noncaseating granulomatous inflammation with no evidence of malignancy on histopathologic examination. Infectious and primary autoimmune etiologies were ruled out. Conclusion and importance: This is a biopsy-proven case of periocular immune checkpoint inhibitor-associated granulomatous inflammation.