Non-Odontogenic Bone Pathology

What Is Your Diagnosis?

“…2 Nonodontogenic lesions that can present as intramedullary, lucent, expansile lesions with cortical bone thinning include fibrous dysplasia, giant cell reparative cysts, giant cell granulomas, simple bone cysts, and ABCs. 3 Based on this patient's age, malignant neoplasms were considered less likely but include chondrosarcoma, fibrosarcoma, and osteosarcoma. 3 In veterinary literature, ABCs have been reported in equine, canine, and feline patients; they commonly affect the metaphysis or diaphysis of long bones but have been reported in the pelvis, vertebrae, and ribs.…”

“…3 Based on this patient's age, malignant neoplasms were considered less likely but include chondrosarcoma, fibrosarcoma, and osteosarcoma. 3 In veterinary literature, ABCs have been reported in equine, canine, and feline patients; they commonly affect the metaphysis or diaphysis of long bones but have been reported in the pelvis, vertebrae, and ribs. 4 The term aneurysmal was used to describe the abnormal ballooned-out appearance of these lesions, similar to the distension in an arterial aneurysm secondary to weakened vessel walls.…”

“…6 Primary lesions have been found to have a rearrangement of the USP6 oncogene, suggesting a neoplastic etiology. 3 However, the pathogenesis of primary ABCs remains unknown, and proposed theories include underlying trauma or hematoma formation secondary to trauma. [3][4][5] Given this patient's history of chewing sticks, trauma as an initiating factor is considered highly likely.…”

“…Curettage and bone grafting used in treatment of primary lesions have been reported with success, though local recurrence rate ranges from 20% to 70%. 3 When planning for surgical resection of the bony lesion, the extent of osteolysis involved should strongly be considered, as pathologic fractures and neuromuscular damage can worsen prognosis. 4 Though documented treatments in veterinary medicine are limited, studies from human literature also suggest that radiation therapy is effective, isolated embolization techniques for specific locations can work, and various intracystic infusions (eg, Ethibloc, polidocanol, zoledronic acid, or absolute alcohol) have shown success comparable to surgical resection.…”