Topical mitomycin chemotherapy for conjunctival malignant melanoma and primary acquired melanosis with atypia: 12 years' experience.

Purpose: To report 12-year follow-up experience with topical mitomycin chemotherapy for diffuse and multifocal primary acquired melanosis (PAM) with atypia and conjunctival melanoma.

Methods: Interventional case series of 16 patients. Mitomycin was a primary treatment for residual epithelial disease in ten patients (eight with PAM with atypia and two with conjunctival melanoma) and as an adjuvant to excision and cryotherapy in six with conjunctival malignant melanoma. Primary treatments consisted of mitomycin 0.04% qid for 28 days (two 14-day cycles) and for 7 consecutive days as adjuvant therapy. Patients were followed for both local recurrence and metastatic disease.

Results: Sixteen patients were followed for a mean 81 months (range 13-144 months) after treatment. All tumors responded to chemotherapy. Recurrence was noted in eight (three adjuvant and five primary treatment patients). Three underwent orbital exenteration. The remaining five were treated conservatively. The mean time to recurrence was 36.9 months. The short-term mitomycin-related complications included transient keratoconjunctivitis (n=14), severe keratoconjunctivitis (n=1) and one corneal abrasion with scar formation. The long-term complications included pannus (n=2) and corneal haze (n=1). Visual acuity was maintained within two lines in 14 patients (including measurements just prior to exenteration). Three patients died, one of metastatic conjunctival melanoma.

Conclusions: Conjunctival melanoma and PAM responded to mitomycin 0.04% topical chemotherapy; subepithelial nests appeared resistant to treatment. Treatment-related complications were acceptable. In this series, as primary and adjuvant therapy, topical mitomycin yielded an overall recurrence rate of 50%.