CASE REPORT Presumed post-traumatic ocular chondrosarcoma with intrathoracic metastases in a cat Matheus V. L. Moreira,* Maria C. de Andrade,* Gustavo O. Fulg^ encio,† Ingeborg M. Langohr‡ and Roselene Ecco* *Section of Pathology, Department of Clinics and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil; †Self-employed Veterinarian, Veterinary Ophthalmology Service, Belo Horizonte, MG, Brazil; and ‡Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA Address communications to: R. Ecco Tel.: +55(31)3409-2261 Fax: +55(31)3409-2230 e-mail: ecco@vet.ufmg.br Abstract An indoor-only, 5-year-old, spayed female domestic shorthair cat presented for an ophthalmic examination of the left eye. An intraocular tumor with secondary glaucoma and blindness was diagnosed; the globe was enucleated and sent for histopathological examination. Gross examination revealed a solid white mass filling the entire vitreous space and replacing the iris and ciliary body. The lens and retina appeared to be simi- larly replaced by the neoplasm. Histological examination revealed a complete loss of the internal ocular structures, with a ruptured capsule as the only remnant of the lens within an extensive malignant mesenchymal neoplastic cell proliferation. The cells were polygonal, with well-defined cytoplasmic borders and abundant weakly basophilic cytoplasm, embedded within the islands of chondroid matrix. No neoplastic invasion of the sclera was apparent. The animal died 6 months after the enucleation due to respiratory distress. Gross examination revealed numerous firm, white to tan nodular masses with smooth to mildly irregular surfaces dispersed throughout the parietal pleura, thoracic surface of the diaphragm, tracheobronchial and mediastinal lymph nodes, pericardium, and lungs. On cross-section, the neoplastic nodules were solid and variably translucent, resembling hyaline cartilage. Histologically, these nodules were similar to the neoplasm identified earlier in the left globe. Metastasis of post-traumatic ocular chondrosarcoma has not yet been described in cats. This is therefore believed to be the first report of metastases of this type of neoplasm in cats. This case adds to the limited set of data on the outcome of this type of tumor. Key Words: feline, metastasis, ocular chondrosarcoma, ocular neoplasia, ocular pathology, post-traumatic ocular sarcoma INTRODUCTION Chondrosarcoma is a malignant mesenchymal neoplasm that produces cartilaginous matrix. It is uncommon in cats and has a slight predilection for male cats. The mean age at which the animals are affected is 9.6 years. Most feline chondrosarcomas affect the skeleton, where they may develop in flat and long bones, with the sca- pula, femur, and digits as the most commonly affected sites. A lower proportion of these tumors are seen in the subcutaneous tissue, some of which are related to vaccination. 1 Ocular chondrosarcoma in cats has been reported as either primary, in the absence of changes indicative of pre- vious lesions in the eye, 2,3 or secondary to trauma. 4,5 According to a recently published case series of presumed primary, nontrauma-related intraocular chondrosarcomas in cats, 3 some of the previously reported cases of intraocu- lar chondrosarcoma classified as primary could actually have been secondary, as post-traumatic ocular sarcoma had not yet been identified as a separate entity at the time of their diagnosis. The first descriptions of this unique ocular condition were only published several years later. 6 In dogs, ocular chondrosarcoma may be primary 7 or © 2017 American College of Veterinary Ophthalmologists Veterinary Ophthalmology (2017) 1–4 DOI:10.1111/vop.12521