Fibroadenomas are typicially homogeneous well defined masses and do not contain internal lucency. Hamaomas are typically well defined mass with interspersed internal lucency, as seen in this patient. Hematomas do not contain central lucency. Acutely, these appear as ill-defined masses at the site of trauma and decrease in size and visibility as they resolve. While galactocele, may contain fat density, this will only occur in a lactating female. A history of lactation (which is unlikely in a 55 year old patient) or fat/fluid level on straight lateral view would be necessary to suggest this diagnosis.