Case Report: Leiomyosarcoma of the Left Upper Eyelid in a Dog

An 11-year-old unneutered male Corgi dog was referred to the Animal Teaching Hospital of National Chiayi University for surgical treatment of the recurrence of an eyelid tumor. The patient continued to scratch the affected area, causing severe damage to the surface of the mass and plenty of bloody fluid and was unwilling to cooperate with physical examination. Through fine-needle aspiration (FNA) cytology under anesthesia, the patient was diagnosed with a malignant spindle cell tumor. Since the tumor had expanded to two-thirds of the upper eyelid and adhered the bulbar conjunctive and the cornea, the veterinarian suggested surgical removal of eyelid mass and enucleation. During surgery, the mass was first freed from the ocular surface and excised along a 1-cm margin, followed by transpalpebral enucleation. Histopathological and immunochemical staining was positive for vimentin and [Formula: see text]-SMA and negative for desmin, CD31, S100 and Melan-A. Therefore, the tumor was identified as leiomyosarcoma (LMS) of the eyelid. After surgery, the dog received metronomic chemotherapy for 30 days. At the 10.5-month follow-up, no sign of recurrence was noted. To the best of the authors’ knowledge, this is the first case report of LMS of the eyelid in canine.