There have been a few reported carcinomas with well-defined borders as well. At times, overlapping trabeculae may obscure the margin of the benign mass but good compression and views with varying degrees of obliquity will help. The radiographic density of a lesion can help determine whether or not the lesion is benign. Fat within a lesion could represent benign pathology such as traumatic oil cysts or lipomas . Examples of a mixed or Isodense lesion would include galactoceles , hematomas , nodes , and hamartomas .
Dense lesions consist of cysts , fibroadenomas , and cancers.
If a benign looking mass does increase in size over time, especially in postmenopausal women, it should be regarded as suspicious. Benign lesions can be associated with microcalcifications, so an increase in the amount of calcification in itself is not necessarily an indication for a biopsy. A prime example is a fibroadenoma. This benign lesion has a tendency to fill up with calcium over time. The key is to note the size and shape of any new calcification.