Fibrosarcoma arising after femur osteosynthesis with pin and plate placement in a cat

Abstract

A 6-year old spayed female Siamese cat was presented with a history of left limb acute lameness. Radiographic imaging revealed a complete comminuted diaphyseal femur fracture, which was corrected through intramedullary pin placement along with plate osteosynthesis. After two months the animal returned to the hospital presenting severe diffuse enlargement of the left hindlimb, characterized as a non-delimited, solid, and firm plaque-like mass surrounding the pin and bone, which extended from the femorotibiopatelar joint to the pelvis, and infiltrated the adjacent musculature. Incisional biopsy exam indicated a highly malignant sarcoma. The entire limb was surgically removed and sent to histopathological evaluation. Microscopically, the mass was composed of spindle shaped cells, displaying high pleomorphism and cellular atypia. Abundant collagen production was evidenced through Masson's trichrome stain and strong cytoplasmic staining for vimentin. These results were consistent with fibrosarcoma. The cat went through one session of chemotherapy; however, tumor recurrence occurred 20 days later, and the animal was submitted to euthanasia. This is the first description of fibrosarcoma arising in the vicinity of an intramedullary pin and plate in a cat.

Feline giant-cell pleomorphic sarcoma: cytologic, histologic and immunohistochemical characterization

“…FISSs are related to the development of tumors after vaccination 15 and substance application, such as cisplatin. 16 Cases associated with surgical materials, such as non-absorbable surgical sutures, 17 surgical sponges 18 and foreign body implants, such as microchips and orthopedic devices, 8,19 have also been described. The latency period between exposure to the inducing agent and development of the tumor is variable for both humans and cats; however, in many cases, there is a long latency period, with the tumor developing months to years after the original insult, 20 which correlates with the average age of the cats in the present study.…”

“…4 PS in cats is considered as a histologic variant of the entity 'feline injection-site sarcoma' (FISS), which comprises tumors that arise as a result of vaccination, drug application or surgical material placement. 7,8 Reports describing clinical behavior, diagnosis and treatment of this type of tumor in cats are scarce, and appropriate diagnostic criteria are essential to proceed with treatment. Therefore, this study aimed to describe the cytologic, pathologic and immunohistochemical (IHC) aspects of giant-cell PS in cats.…”

“…4 PS in cats is considered as a histologic variant of the entity ‘feline injection-site sarcoma’ (FISS), which comprises tumors that arise as a result of vaccination, drug application or surgical material placement. 7,8…”