Abnormal humerus morphology Cystic changes in greater tuberosity of the humerus 2025-10-26T18:48:12Z Cystic lesions of the proximal humerus are commonly encountered on routine shoulder magnetic resonance imaging (MRI). True cysts are defined as fluid-filled structures or lesions with an epithelial lining, whereas pseudocysts are fluid-filled lesions without epithelial lining. Cystic lesion encompasses both true cysts, pseudocysts and other lesions which could mimic the appearance of a cyst on MRI, with increased signal on fluid sensitive sequences. Cystic lesions of the humeral head are commonly encountered on routine shoulder magnetic resonance imaging (MRI). Differential diagnoses include degenerative lesions, calcific tendinitis with osseous involvement, perianchor cysts, abscesses and less often, tumours. Degenerative lesions, including subcortical and subchondral cysts, are the most commonly encountered. These may be associated with rotator cuff disease and degenerative joint diseases or considered part of ageing depending on the location of the cystic lesions.