Hypertrophic Osteopathy in a Cat

Abstract

Background: Hypertrophic osteopathy (OH) is a syndrome characterized by progressive bilateral periosteal bone neoformation that mainly affects the thoracic and pelvic limb bones' metaphyses and diaphyses. In most cases, it is secondary to a chronic primary lesion located in the thoracic cavity but can be associated with an abdominal injury that has already been occurred. The occurrence of this condition without being associated with a primary lesion is considered infrequent in animals. The purpose of this report was to describe a case of idiopathic hypertrophic osteopathy in a cat with a description of clinical signs and radiographic and anatomopathological findings. Case: A male adult cat was brought to the veterinarian with an initial observation by the owner of four limbs' volume increase, apathy, and reluctance to move. Upon clinical examination, the animal presented dehydration, mucosal hyperemia, hyperthermia, and bilateral edema of the thoracic and pelvic limbs. Based on the radiographic examination, a periosteal reaction with palisade-like appearance was found in the metacarpals, radios, ulna, humerus, scapulae, tibias, and fibulae. There were no significant changes in additional exams. Due to poor prognosis, the cat was euthanized and referred for necropsy and histopathological examination. All organs were examined both macroscopically and microscopically. Fragments were fixed in 10% formalin and routinely processed for histological slides with hematoxylin-eosin and Masson's trichrome, and limb bones that were not fixed in formalin were macerated. Lesions were observed only in the thoracic and pelvic limbs. Macroscopically, there was a diffuse, regular, slightly firm volume increase, covered by abundant gelatinous whitish tissue. The periosteal bone neoformations were characterized by numerous papillary projections distributed throughout the phalanges, radius, ulna, humerus, scapulae, tibia and fibulae. Histologically, the original bone matrix was surrounded by lightly organized eosinophilic material in bundles. Young bone matrix-formed trabeculae perpendicular to the original bone matrix, projecting into the mature bone tissue, was attached to the cortical layer. Discussion: The hypertrophic osteopathy diagnosis was based on clinical signs, radiographic examinations, and anatomopathological findings. Although the long bones of the pelvic limbs are often the most affected, the lesions were more marked in the thoracic limbs in this cat. The presumptive diagnosis was made through radiographic examination. Radiography is considered a very useful diagnostic method in animals suffering from this condition. Histological changes are compatible with persistent phases of hypertrophic osteopathy resulting from the action of osteoclasts and osteoblasts, with osteoid matrix deposition in the existing cortical bone. Since this cat didn't present macroscopic and microscopic alterations beyond the bone lesions, it was not possible to attribute them to a primary cause. For this reason, osteopathy was considered idiopath...

Hypertrophic Osteopathy Associated with Lung Adenocarcinoma in a Cat: An Overview

“…Hypertrophic osteopathy in our case was symmetrical, with the front and hind limbs equally affected, however the phalanges were not affected at all, which is consistent with other similar studies [2,3,23]. Hypervitaminosis A is the principle differential diagnosis of the periosteal proliferation [23].…”

“…Hypertrophic osteopathy (HO) was fi rst described in humans in 1800 and is known by various names: hypertrophic osteoarthropathy, osteoporotic deformities, acropachy and Pierre Marie-Bamberger syndrome [1]. It is a pathological condition characterized by progressive, bilateral and symmetrical periosteal bone hyperostosis affecting mostly the diaphyses and metaphyses of the long bones of the forelimbs and hindlimbs [2,3]. Although diffuse periosteal hyperostosis is not characterized by changes in the continuity of the bone compact tissue, it could still lead to varying degrees of lameness in the animal [1].…”

Feline Hypertrophic Osteopathy Associated with Congenital Megaesophagus: Two Case Reports and Literature Review

“…Moreover, four reports of idiopathic HO have been recorded (Table 1). The prognosis of HO in cats is poor as most of the recorded cases were died shortly afterwards (Richards, 1977;Gram et al, 1990) or euthanized at the owner's request at the time of diagnosis (Carr, 1971;Roberg, 1977;de Melo et al, 2006;Guizelini et al, 2019). However, medical and surgical treatments were successful six months after their initiation in few cases of HO (Becker et al, 1999;Grierson et al, 2003;Huang et al, 2010;Mills 2010).…”