TITLE: 
                        
                            Solid Aneurysmal Bone Cyst of the Distal Metatarsus in a Horse
                                
                                
                                    AUTHORS: 
                                            Nadja Herbach, Christina Terboven, Peter Lambrecht 
                                                    
                                                        KEYWORDS: 
                        Bone Tumor, Aneurysmal Bone Cyst, Horse 
                                                    
                                                    
                                                        JOURNAL NAME: 
                        Open Journal of Pathology,  
                        Vol.6 No.2, 
                        April
                                                        18,
                        2016
                                                    
                                                    
                                                        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.