From Keratoma to Anaplastic Malignant Melanoma in a Horse’s Hoof
Elżbieta Stefanik,
Kamil Górski,
Bernard Turek,
Olga Drewnowska-Szczepakowska,
Katarzyna Kliczkowska-Klarowicz,
Aleksandra Stefanik
Affiliations
Elżbieta Stefanik
Department of Large Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences, 02-787 Warsaw, Poland
Kamil Górski
Department of Large Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences, 02-787 Warsaw, Poland
Bernard Turek
Department of Large Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences, 02-787 Warsaw, Poland
Olga Drewnowska-Szczepakowska
Department of Large Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences, 02-787 Warsaw, Poland
Katarzyna Kliczkowska-Klarowicz
Division of Pathology, Department of Pathology and Veterinary Diagnostis, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-776 Warsaw, Poland
Aleksandra Stefanik
Zagłębie Oncology Centre, Szpitalna 13, 41-300 Dąbrowa Górnicza, Poland
Melanomas in horses are most often associated with gray, older horses with an average age of over 16 years. Anaplastic malignant melanoma, however, can very rarely affect non-gray horses. Herein, we report a case of a 16-year-old Wielkopolski gelding with a chronic lameness caused by a mass in the hoof. The first resection of the lesion and histopathological examination confirmed the presence of a keratoma. The regrown mass and persistent lameness resulted in another mass resection. The second histopathological examination result suggested a neoplastic growth of melanocytic origin with a low histological malignancy. Less than 2 years after the first resection, the horse returned to the clinic with deformation of the hoof capsule and severe lameness. The result of the third histopathological examination indicated low-differentiated malignant neoplasm. The result of the immunohistochemically test indicates a tumor of melanocytic origin with high malignancy.
