Abstract
A 14-year-old, spayed female mongrel dog presented with a mass on the inner aspect of the upper eyelid of right eye, occupying about 70% of the area of the palpebral fissure. Histopathologic examination of the biopsy specimen showed that the mass was consisted of multiple lobules of large tumor cells with many cytoplasmic vacuoles. There were no small basaloid cells in the tumor tissue. These tumor cells showed nuclear atypia, mitotic activity, and some of these showed positive reaction for proliferating cell nuclear antigen by immunohistochemistry. Based on these findings, the tumor was diagnosed as a meibomian carcinoma. The tumor cells were differentiated, and might be resemble sebocytes or meibomian gland cells. Therefore, even sebocyte-like tumor cells without mitotic activity are detected in cytology, histopathologic examination may be required for the diagnosis of the cases with unusual clinical appearances.
