Case report 673

Abstract

Fig. l.A frontal plane view roentgenogram shows an expanding, lyric lesion with a minima1 intralesional density and a sclerotic rim in the proximal portion of the left third metatarsal Fig. 2. A lateral view roentgenogram shows a bulging, thin, and eroded cortex with minimal intralesional density and periosteal reaction is the left third metatarsal Clinical informationA 4-year-old, 70 kg, male Great Dane dog was studied for lameness in a left rear limb and a firm, painful swelling of the left metatarsal region of several weeks' duration. The lameness and swelling were partially responsive to antibiotic treatment. On physical examination, a palpable mass approximately 1.5 x 3.5 cm was noted with tenderness to palpation but no associated redness.Radiographs of the left metatarsus revealed an expanding, lyric lesion in the third metatarsal bone. Bulging of the anterior surface corresponded to the palpable mass. The cortex was thin and eroded in areas with minimal periosteal reaction and sclerosis in the proximal region of the third metatarsal bone (Fig. 1, 2).A surgical biopsy of the lesion was performed,

Malignant Transformation of an Aneurysmal Bone Cyst in a Dog

“…Aneurysmal bone cysts are benign lesions reported frequently in humans but rarely in horses, cattle, dogs, and cats 1–11 . Grossly, they are blood‐filled sponge‐like lesions of variable size partially or completely destroying the parent bone.…”

Case report 775

“…The median age of presentation of osteosarcomas in 398 dogs was 8+0.7 years [6,7], so the young age of this dog is very unusual. The age of the dog, the breed, and the site are atypical.…”

“…As in hulnan osteosarcomas, canine osteosarcomas are typically ill-defined destructive lesions with cortical destruction, periosteal reaction, and variable osteoblastic matrix formation [2,7,9]. As in hulnan osteosarcomas, canine osteosarcomas are typically ill-defined destructive lesions with cortical destruction, periosteal reaction, and variable osteoblastic matrix formation [2,7,9].…”

“…Biopsy specimen from femoral head. In 368 can-ine osteosarcomas, 63% occurred in 7 breeds of large dogs[6,7]. The spindle cells are varied in size and morphology with some hyperchromatic nuclei and others with prominent nucleoli.…”

Right ventricular rupture after lateral thoracotomy for removal of rib‐associated telangiectatic osteosarcoma in a dog

“…Similar data for veterinary medicine do not exist. In dogs, TOS has been reported to occur in different anatomical locations, including the tibia, scapula, mandible, thoracic wall, third metatarsal bone, seventh cervical vertebra, and multifocally 8–13 . Myocardial rupture in conjunction with a TOS has not been described in humans or animals.…”