[Two cases of conjunctival malignant melanoma treated with topical interferon alpha-2b drop as an adjuvant therapy].

Topical interferon alpha-2b (IFNalpha-2b) eye drops suppress tumor growth through the activation of host immunity on the ocular surface. Conjunctival malignant melanoma, a rare malignant tumor in Japan, develops local recurrence and lymph node metastasis. We herein report two cases with conjunctival melanoma treated with topical IFNalpha-2b eye drops. Case 1, a 77-year-old woman presented with temporal conjunctival pigmented nodules, simulating primary acquired melanosis (PAM) on the cornea and around the conjunctiva OD. Case 2, an 84-year-old woman, presented with nasal conjunctival pigmented nodules and PAM OD. Both patients underwent tumor excision and IFNalpha-2b drops four times per day for half a year. Histologically, the excised conjunctival nodules of both patients were diagnosed with malignant melanoma. There was no local recurrence or distant metastasis 24 months after tumor resection. Topical IFNa-2b is a useful adjuvant treatment in patients with conjunctival malignant melanoma, following tumor resection.