From the Guidelines
A type 3 kinetic mammogram indicates a probably benign finding, with a less than 2% risk of malignancy, and short-interval follow-up is suggested to ensure the stability of the finding. This assessment is based on the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS) Atlas, as described in the study by 1. The BI-RADS category 3 is reserved for findings that are likely to be benign but require close monitoring to confirm their stability.
The management of a type 3 kinetic mammogram typically involves diagnostic mammograms at 6 months, then every 6 to 12 months for 1 to 2 years, as recommended by 1. If the lesion remains stable or resolves mammographically, the patient can resume routine screening intervals for mammography. However, if the lesion increases in size or changes its benign characteristics, a biopsy is typically performed to rule out malignancy.
It is essential to note that the BI-RADS assessment categories are used to standardize the reporting of mammography results, and category 3 is not indicative of malignancy but rather a finding that requires further monitoring. The study by 1 provides a comprehensive overview of the BI-RADS assessment categories and their corresponding management recommendations.
In clinical practice, the management of a type 3 kinetic mammogram should be individualized based on patient factors, such as family history and personal anxiety level, as well as the specific characteristics of the lesion. The study by 1 emphasizes the importance of considering these factors when determining the appropriate follow-up strategy for a patient with a type 3 kinetic mammogram.
Overall, a type 3 kinetic mammogram is a probably benign finding that requires short-interval follow-up to confirm its stability, and patients with this finding should follow up promptly with their healthcare provider to discuss next steps in their diagnostic workup, as recommended by 1.
From the Research
Definition of Type 3 Kinetic Mammogram
- A type 3 kinetic mammogram refers to a Breast Imaging Reporting and Data System (BI-RADS) category 3 assessment, which is used for breast imaging findings considered "probably benign" with less than a 2% likelihood of malignancy 2.
- BI-RADS category 3 lesions are recommended for short-interval follow-up after a diagnostic workup has been completed 3.
Characteristics of BI-RADS Category 3 Lesions
- In mammography, category 3 findings are validated for grouped round calcifications, oval circumscribed masses, and nonpalpable asymmetries 2.
- In US, category 3 can be applied to oval circumscribed parallel solid masses and complicated cysts 2.
- Category 3 can be assigned to clustered microcysts when they are very small or deep in the breast 2.
- Recent studies have yielded characteristic findings appropriate for MRI category 3, including oval circumscribed masses with associated T2-hyperintense signal, focal non-mass enhancement, and foci of enhancement with associated T2-hyperintense signal 2.
Use of BI-RADS Category 3 in Clinical Practice
- The use of BI-RADS category 3 is appropriate, with a cumulative cancer yield of 1.86% through 2-year follow-up 4.
- Short-interval follow-up of mammographic BI-RADS category 3 findings is necessary, with 57.8% of malignancies diagnosed at or before 6 months 4.
- BI-RADS category 3 should not be used in a screening study without a comprehensive diagnostic evaluation that may reveal suspicious features or downgrade a finding to benign 2.
Problem-Solving Modality
- Breast MRI can be used as an adjunctive tool to mammographic BI-RADS 3 findings to exclude patients for further diagnostic work-up 5.
- The negative predictive value (NPV) of MRI is highest of all imaging techniques, but it is not yet common practice to use breast MRI as a problem-solving modality to exclude patients for further diagnostic work-up 5.