ABSTRACT
A 13-year-old cat was diagnosed with a synovial cyst originating from the glenohumeral joint. The cat presented with severe front limb lameness and a non-painful fluctuating swelling on the medial aspect of the humerus. Radiographic examination showed severe bilateral shoulder osteoarthritis with osteophyte formation. The mass was surgically resected and histopathology confirmed the diagnosis of a synovial cyst. Three weeks postoperatively the cyst recurred. Surgical resection was repeated followed by omentalisation of the defect. Throughout the following 3 months the cyst did not recur. Unfortunately, for reasons unrelated to the presented disease, the cat was euthanized shortly afterwards, therefore making a long-term follow-up impossible.
