Orbital extraskeletal osteosarcoma following enucleation in a cat: a case report

Abstract

Following the enucleation, retained conjunctival epithelium became embedded in the connective tissue of the orbit and caused a cyst to develop. The cyst wall consisted of a myofibroblastic collagen-rich matrix and acted as a nidus of chronic irritation and tumor growth. This orbital osteosarcoma resembles feline vaccine-associated sarcomas (VAS), feline post-traumatic ocular sarcomas, and microchip-associated sarcomas in terms of it histopathology and its hypothesized pathogenesis related to exposure to antigenic material such as implanted epithelium, lens protein, vaccine components, and microchips as foreign bodies.

Origins of Injection-Site Sarcomas in Cats: The Possible Role of Chronic Inflammation—A Review

“…All of this may suggest that the cat has a genetic predisposition to injection-site-related sarcomas, or at least to the damage related to injection which ultimately predisposes to sarcomagenesis. This may help to explain the cat's susceptibility to ocular sarcomas, some of which occur at the site of previous trauma [382–388]. …”

Spontaneous Extraskeletal Osteosarcoma in a Rabbit (<i>Oryctolagus cuniculus</i>): Histopathological and Immunohistochemical Findings

“…Extraskeletal osteosarcoma (ESOS) is a rare malignant mesenchymal neoplasm, which is never attached to the skeleton, although the histopathological characteristics such as osteoid and bone formation are similar to those of bone-derived osteosarcomas 5 , 6 . ESOS has been reported in dogs, cats, hamsters, a rat, a hedgehog, a maned wolf and a goat as an infrequent tumor 7 , 8 , 9 , 10 , 11 , 12 .…”

Extraskeletal Osteosarcoma: A Rare Case Arising in Phthisis Bulbi with a Review of the Literature

“…In 2000, Long et al [5] reported an 86-year-old woman with extraskeletal osteosarcoma following a 20-year history of phthisis bulbi secondary to multiple ocular procedures and uncontrolled glaucoma. While earlier descriptions of extraskeletal osteosarcoma arising in phthisical eyes in felines have been reported [6][7][8], Long et al's report is the only other example involving a phthisical human eye. Similar to our case, their patient's presentation included pain and proptosis.…”