Abstract
A horse was presented with a slowly growing mass of the distal metatarsal region of the right hind leg. Radiographic examination revealed an eccentric cyst-like lesion with distortion of the lateral margin of the distal metatarsus. The lesion involved approximately half of the metatarsal width, exhibited fine septa, a sclerosed margin towards unaffected bone and a smooth rim of thin compact bone at the periphery. Longitudinal sectioning of the distal metatarsus revealed a solid pale yellow mass with reddish foci and margin. Histologically, the mass consisted of a cell-rich, well vascularized fibrous stroma, containing numerous irregularly shaped trabeculae of woven bone with regular osteocytes. Osteoblasts were observed around the osteoid, and there were foci of numerous osteoclast-like giant cells. The lesion was diagnosed solid variant of an aneurismal bone cyst.
Highlights
According to the WHO, aneurismal bone cysts (ABC) are benign cystic bone lesions, containing blood filled cavities and fibrous septa composed of fibroblasts, reactive woven bone and osteoclast-like giant cells [1]
ABC have rarely been observed in horses, and were described in long bones, including two cases reporting on ABC of the third metatarsal bone of foals [3] [4], another foal exhibited an ABC in the third metacarpal bone and one in the tibia [5] and a 9 year old horse showed an ABC with pathological fracture in the radius [6]
ABC is a rare disease of horses; an age- or sex-predilection is not known
Summary
According to the WHO, aneurismal bone cysts (ABC) are benign cystic bone lesions, containing blood filled cavities and fibrous septa composed of fibroblasts, reactive woven bone and osteoclast-like giant cells [1]. (2016) Solid Aneurysmal Bone Cyst of the Distal Metatarsus in a Horse. ABCs are rarely reported in domestic animals, including dogs, cats, horses, and cattle [2], and appear similar to the lesion in humans [1]. ABC may arise de novo (primary ABC) or complicate other benign or malignant bone tumours (secondary ABC) in humans and animals, e.g. giant cell tumours, osteoblastoma and fibrous dysplasia [1] [2]. The present report describes a solid aneurismal bone cyst of the distal metatarsus in a horse
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
