PATHOLOGICAL STUDIES ON SOME EQUINE SKIN TUMORS

Abstract

The present study was carried out to give spotlight on different types of cutaneous neoplasms in equines in Egypt. For this purpose, sixty-three cases of equine cutaneous neoplasms were collected from different locations in Egypt (Zahraa farm, Giza Zoo, Military Vet. Hospital, Brooke Hospital and different Vet. Clinics). Surgical removal of these skin tumors was carried out and followed by preparation of tissue samples for pathological investigation. The pathological examination showed that the most predominant types of equine skin tumors were sarcoids which represented 58.73% of all equine cutaneous tumors. The general cutaneous changes in all types of sarcoids were the intensified dermal proliferation. The next type was fibroma which was seen at a percent of 12.69 % in both soft and hard forms with characteristic fibrous connective tissue proliferation in association with collagen production in variable amounts. The vascular tumor was detected at a high percentage (11.11%), microscopic examination showed high degrees of vascular channel proliferations of different sizes. The detected types were capillary and mixed hemangiomas. Papilloma at a percent of 7.9 % was also observed and showed hyperkeratosis, finger-like projections, marked hyperplasia of the epidermis and intracellular keratohyaline material. Squamous cell carcinoma was detected at 4.75 % in two types: well-differentiated and anaplastic forms. Regarding melanoma, it was also seen in two forms depending on the melanocytes and melanophages location in the dermis.