Resolution of primary acquired melanosis with atypia after treatment with topical mitomycin C and interferon alfa-2b

Purpose: To report a case of primary acquired melanosis (PAM) successfully treated with combined topical mitomycin C and interferon-α2b.

Case report: A 75-year-old man presented with an extensive unilateral pigmented lesion involving 360° of the bulbar conjunctiva, extending to the fornices and palpebral conjunctiva. Map biopsy confirmed PAM with local atypia. Treatment was initiated with mitomycin C 0.04% eye drops for two courses. Although the lesion markedly responded to the treatment, residual lesions justified further therapy. To avoid ocular surface toxicity induced by excessive mitomycin C exposure, interferon-α2b eye drops were started and continued for 6 months. The pigmented lesion almost completely disappeared and no significant complication or recurrence was observed for 24 months.

Conclusion: Combination therapy using mitomycin C and interferon-α2b for PAM with atypia may be recommended as an effective treatment modality, avoiding the ocular surface toxicity due to excessive mitomycin C exposure.