Non-palpable breast lesions

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With increasing use of screening mammography and ultrasound for various indications, a large number of non-palpable breast lesions are being detected.

Among this large number of non-palpable masses, not all are malignant. The incidence of malignancy among these non-palpable lesions varies between 20-30%.

The radiologist plays an important role in the further work up and management of this subset of patients.

Radiologists role

What role can we as radiologists play?

  • be careful in evaluating any breast lesion; comparison with previous images is invaluable; lesions that change over time is a significant finding but is not necessarily a predictor of malignancy.
  • be sure not to overdiagnose
  • rule out pseudo mass lesions; if necessary, perform extra views in mammography like magnification views
  • use ultrasound to correlate the abnormal findings on mammography.
  • can perform wire needle localization of non-palpable lesions detected by mammography which are not seen on ultrasound
  • can use same procedure of stereotactic biopsy to place a hook wire in the center of the lesion
  • following the excision, can do specimen mammography to ensure that there is an adequate margin by comparing the specimen mammogram with the preoperative mammograms
  • the suspicious lesion may be just a cluster of microcalcifications
  • in such cases, we need to be careful evaluating adequate margins on specimen mammogram
  • in lesions seen on mammography, needle placement can be done under sonographic guidance. In such cases, intraoperative sonography can be performed to assess complete removal
  • ultrasound-guided FNAC/biopsy can be performed preoperatively.
  • recent technique of radionuclide localization (ROLL) is emerging as an adjunct.

Triple assessment

To be convinced a lesion is benign, the lesion has to always be benign/innocuous on

  • clinical exam
  • breast imaging, i.e. mammography, ultrasound and or MRI or a combination of each
  • tissue sampling (cytology or histology)

If one of the three bullets above is not satisfied, the lesion cannot simply be called benign. If the lesion is clinically suspicious and even if imaging is negative, cytology is indicated. If the lesion is palpable and not seen on mammogram ultrasound is mandatory and unless the ultrasound is convincingly benign, tissue sampling is indicated.