Aggressive osteoblastoma of the cervical vertebrae in a Turkish Angora cat

Abstract

A 7-year-old castrated male Turkish Angora cat was referred to the Veterinary Teaching Hospital of Konkuk University (Korea) with a 3-month history of rightforelimb monoparesis. The patient showed neurological deficits in the right forelimb, except for digital deep-pain perception, and could not ambulate normally. Blood cell count, serum biochemistry, and electrolyte results were within the reference ranges.Radiography showed bony proliferation at the ventral margin and lateral transverse region of the vertebral bodies

A complex histopathological challenge: suspicion of an osteoblastoma-like osteosarcoma arising from the second thoracic vertebra in a cat

“…In human medicine, COX-2 positivity has been used to distinguish between aggressive osteoblastoma and low-grade osteosarcoma, being the first COX-2 positive and the second COX-2 negative [31]. Kim et al in 2017 [24] used this immunohistochemical method to diagnose an aggressive osteoblastoma in a cervical vertebra in an Angora cat. Unfortunately, in our case immunohistochemistry failed to result in a definitive diagnosis.…”

“…Although reimaging indicated a recurrence of the mass, the spinal cord was still not compressed. Surgical treatment of spinal bone tumour reported in cats includes an hemilaminectomy [24] in a cervical aggressive osteoblastoma and an hemilaminectomy followed by a vertebral replacement in a L1 osteosarcoma [53]. Recurrence was described two and 3 years after the initial surgery, respectively.…”

“…Osteosarcoma is the most common vertebral tumour in the cat. In contrast, veterinary reports of osteoblastic tumours are restricted to a few case reports [ 8 – 12 , 24 , 30 ].…”

“…Osteoblastoma-like osteosarcoma (OBLOS) has been defined in human literature as a malignant tumour, that share features between both, osteosarcoma and osteoblastoma and have the potential for metastasising [19,23]. The term "aggressive osteoblastoma" was first introduced into veterinary literature describing a vertebral neoplasia in a cat by Kim et al [24]. Aggressive osteoblastoma invades adjacent tissue and recurs but, in contrast to OBLOS, does not metastasize [25].…”