A Case of Sebaceous Carcinoma Detected on the Eyelid of a Horse

DOI:  10.26650/actavet.2018.2808 This article describes a case of sebaceous carcinoma located on the right lower eyelid of an 11-year-old female Haflinger horse and its surgical, clinical, and histopathological aspects. The Haflinger horse was referred to the clinics of the Department of Surgery with a complaint of a swelling on the right lower eyelid, which had been present for 1 year and began to grow during the past few months. A clinical inspection revealed a soft, multinodular tumoral mass, with the dimensions of 4×5 cm, located in the inferior region of the right lower eyelid and protruding outward. The surgical removal of the mass was decided after the clinical inspection. The excised tumoral mass was submitted to the department of pathology for histopathological evaluation, which revealed well-circumscribed multilobular structures comprising foci of round-to-ovoid and polygonal pleomorphic neoplastic epithelial cells with prominent nuclei and eosinophilic cytoplasm separated by bands of the fibrous tissue of varying thickness. There was prominent cellular pleomorphism; some cells contained cytoplasmic vacuoles of various sizes, whereas some exhibited sebaceous differentiation. Based on these histopathological findings, sebaceous carcinoma of the sebocyte type was diagnosed.