Topical chemotherapy using cisplatin for treatment of malignant melanoma in a grey horse

A 7-year-old grey horse was referred to Kyungpook National University Veterinary Teaching Hospital due to two slowly growing pigmented masses located on her tail. At presentation, about 2 cm in diameter round dome-shaped masses with firm consistency were visualized and palpated one on the dorsal tail root on Co5 and the other on ventral proximal tail, between Co6 and Co7 area. A fine needle aspiration (FNA) biopsy confirmed malignant melanoma. A series of four topical chemotherapy with 2-week intervals was conducted using cisplatin in water-sesame seed oil emulsion. The tumor sites appeared healed with no signs of recurrence of tumor 6 weeks after completion of the treatment. To our knowledge, this is the first report of a treatment of the malignant melanoma using cisplatin in a horse in Republic of Korea.