Benign breast lesions are extremely common. Mammography is predominantly used for imaging. An overview of classification and image-based diagnosis.
Benign breast lesions are extremely common. Mammography is predominantly used for imaging. A review of classification and image-based diagnosis.
For better comprehension, the current nomenclature and its meaning will first be considered for radiological reporting of the mamma. These apply to benign and malignant changes.
In 1997, the American College of Radiology (ACR) standard for the Breast Imaging Reporting and Data System (BIRADS) was published, and has been updated several times since then. This made it possible to objectify and standardize the reporting by radiologists. The standard is now accepted worldwide. With the fourth edition in 2003, the definitions of terms and classifications were also applied to mammary sonography. In 2014, the update was made with the fifth edition [1]. Table 1 lists the BI-RADS categories and their meaning.
The German S3 guideline for early breast cancer detection requires histological confirmation by vacuum or punch biopsy for all BI-RADS 4/5 findings. If there is incongruence of clinic and imaging, cancer anxiety of the patient, or an appropriate risk profile, biopsy may be performed even in BI-RADS 3 [2].
The ACR classification describes the proportion of glandular tissue in the mammogram (Overview 1).
These imaging tools provide (mostly) clarity
Modern imaging mammography examinations are now primarily performed with digital flat-panel detector mammography, which requires only the lowest dose compared with conventional film mammography and imaging plate mammography [3]. Tomosynthesis is helpful for dense mammary structures. For breast sonography, a device with a high-resolution transducer and color Doppler option is required. Ultrasonography can very well differentiate solid focal findings from cysts, and color-coded Doppler can provide a species-diagnostic assignment of pathologic lymph node enlargements.
Breast MRI has three specific indications with very good assessability of findings:
- Suspicion of local recurrence in condition after breast-conserving therapy (BET)
- Condition after prosthesis implantation after therapy
- Histologically confirmed axillary lymph node metastases without evidence of a primary breast tumor in mammography and/or sonography
Bioptically confirmed malignancies of the breast prior to surgical treatment are also a reasonable medical indication for breast MRI in order to exclude multifocal or contralateral tumors.
Galactographies can be used in cases of bloody mammillary secretions to clarify inflammatory or space-occupying processes of the mammary duct system. Fine needle aspiration for cytological and punch biopsy for histological examination complete the examination methods commonly used in practice.
Overview 1 lists some benign findings of the mamma [4,5], and several findings are documented in the case reports.
Take-Home Messages
- Numerous benign changes can occur in the mamma.
- In most cases, diagnoses are to be made after taking a history, clinical and imaging examination.
- Mammography, tomosynthesis and sonography represent the basic imaging procedures. As a very sensitive and specific procedure, breast MRI is used as a complementary method for specific questions.
- In the case of clinically and mammographically similar findings, sonography can usually confirm the differential diagnosis, especially in the case of dense mammary structure.
- Standardized classification of findings is performed according to BI-RADS and ACR.
Literature:
- American College of Radiology: ACR BI-RADS Atlas®5th Edition. www.acr.org/Clinical-Resources/Reporting-and-Data-Systems/Bi-Rads, last accessed 5/13/19.
- AWMF: Interdisciplinary S3 guideline for early detection, diagnosis, therapy and follow-up of breast carcinoma. Version 4.1, September 2018. www.leitlinienprogramm-onkologie.de/leitlinien/mammakarzinom, last accessed 5/13/19.
- Hahn D: Bayerisches Ärzteblatt 2008; 2: 72-76.
- Fischer U, ed.: X-ray mammography. Understanding, applying and optimizing. Stuttgart/New York: Georg Thieme Verlag, 2003: 91-131.
- Heywang-Köbrunner SH, Schreer I: Imaging breast diagnostics. Examination technique, pattern of findings and differential diagnosis in mammography, sonography and magnetic resonance imaging. Stuttgart/New York: Georg Thieme Verlag, 1996: 172-201.
GP PRACTICE 2019; 14(6): 35-37
