Occurrence of ocular and adnexal neoplasms in canines with special reference to pigmented sebaceous gland epithelioma of eyelids

Abstract

The eyelid tumours are uncommon in dogs. In the present study, out of 102 ocular and adnexal samples from the dogs examined for a period of 2.5 years, 11 cases (10.78 per cent) were neoplastic in nature. The major location of the neoplasms was eyelids (8/11). One case (0.98 per cent) was diagnosed as pigmented sebaceous gland epithelioma. The tumour mass was present in the palpebral conjunctiva of the lower eyelid near the medial canthus of the left eye in a five-yearold Labrador dog. Grossly, the tumour mass appeared to be a greyish-black, firm, cauliflower-like growth. The mass was resected and submitted for histopathology. Microscopic examination of the mass showed a preponderance of basaloid reserve cells in the tumour tissue. The proliferating reserve cells formed irregular islands or trabeculae separated by thin fibrous connective tissue. They showed minimal to no pleomorphism, scanty amphophilic cytoplasm and oval nuclei. Melanin-containing cells were frequent, while mature sebocytes were infrequent. Mitotic figures were occasional. Pigmented sebaceous gland epithelioma was diagnosed based on gross and histopathological features. Apart from this, neoplasms such as fibrosarcoma, meibomian gland adenocarcinoma, well differentiated squamous cell carcinoma, papilloma and non-pigmented sebaceous gland epithelioma involving eyelids, histiocytoma of third eyelid, periglobular lymphoma and leukemic infiltration of choroid were also recorded. The present research underlines the lower incidence of eyelid tumours in dogs.