• D'Orsi CJ, Bassett LW, Berg WA, Bohm-Velez M, Evans WP III, Farria DM, Lee C, Mendelson EB, Goldstein S. Nonpalpable breast masses. [online publication]. Reston (VA): American College of Radiology (ACR); 2005. 12 p. [25 references]

This is the current release of the guideline.

It updates a previously published version: D'Orsi C, Mendelson E, Bassett L, Bohm-Velez M, Cardenosa G, Evans WP 3rd, Monsees B, Thurmond A, Goldstein S. Work-up of nonpalpable breast masses. American College of Radiology. ACR Appropriateness Criteria. Radiology 2000 Jun;215 Suppl:965-72.

The appropriateness criteria are reviewed annually and updated by the panels as needed, depending on introduction of new and highly significant scientific evidence.

ACR Appropriateness Criteria®

Clinical Condition: Work-up of Nonpalpable Breast Mass

Variant 1: Focal asymmetries.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 2: Round, oval or lobular mass with circumscribed, partially obscured margin on baseline screening mammogram.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 3: Spiculated and/or ill-defined masses.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 4: Circumscribed (> 75%), partially obscured mass with coarse, dystrophic and/or "popcorn" calcification.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 5: Circumscribed/partially obscured mass with pleomorphic/amorphous and/or heterogeneous calcifications.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 6: Irregular spiculated/indistinct mass with coarse/dystrophic and/or "popcorn" calcification.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 7: Irregular spiculated/indistinct mass with pleomorphic/amorphous and/or heterogeneous calcification.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

With improved imaging techniques, screening mammograms enable early detection of smaller cancers. Most lesions detected mammographically are benign. The positive predictive value of mammography for breast cancer ranges from 10%-15% to 34%-40% depending on age and type of population examined.

Normal soft-tissue densities can simulate a mass, and additional mammographic and/or US evaluation may be necessary to determine the presence of a true mass. Masses are three-dimensional structures with convex outward contours. Asymmetric breast tissue is planar, often with concave outward contours. When a new mass is suspected, additional imaging is necessary using additional views and possibly ultrasound. When a mass is detected mammographically, assessment of its shape, margin, density, and size should be done as outlined in the American College of Radiology (ACR) BI-RADS® Atlas, Appendix I in the original guideline document.

Ultrasound has the ability to determine the cystic or solid nature of a breast mass. Adhering to strict criteria, this technique can separate cystic from solid masses with an accuracy approaching 100%. Using good-quality, high-frequency equipment, cysts as small as 2-3 mm in diameter can be demonstrated. After final mammographic evaluation, round, oval, or lobular masses with circumscribed or partially obscured or ill-defined margins can be further investigated with US to identify simple cysts, complicated cysts, complex masses, and solid masses. Masses with mammographic findings that are suspicious or highly suggestive of malignancy, or masses with suspicious or typically benign calcifications, do not require US for assessment, though US can be used to guide needle biopsy if the mass is seen sonographically.

The data on the use of MRI to evaluate nonpalpable masses is being addressed. Current uses of MRI include evaluation of disease extent in the ipsilateral and contralateral breasts in women with known malignancy and screening of high-risk women with dense breasts, although benefit has not been established.

After appropriate work-up of a mass, which will usually include diagnostic mammography and US, a final assessment following BI-RADS® guidelines should be assigned. Articles have validated the approach of following probably benign lesions, as outlined in the ACR BI-RADS® Atlas--Mammography, 4th Edition guidance chapter, to decrease the number of biopsies of benign lesions and potentially substantially reduce cost. If the mass is placed in category 4 or 5, a biopsy is warranted. This biopsy may be incisional using stereotactic or US guidance to obtain a core of tissue or cellular aspirate via fine-needle technique. An incisional biopsy should only be done if the diagnostic process is shortened and/or more cost effective with comparable outcome to an excisional biopsy. For example, if a solid mass is diagnosed as fibroadenoma on core biopsy and then undergoes surgical excision for any of a variety of reasons, cost has been added and the diagnostic procedure has been lengthened with no gain. On the other hand, a core biopsy may be used to provide histology for a category 5 lesion so that excision and sentinel node biopsy can be done simultaneously. Where sentinel node biopsy will not be performed, a category 5 lesion may be directed to excision without a prior core biopsy.

There are advantages and disadvantages to core and FNAB techniques. An advantage to core biopsy is that it does not require a trained cytopathologist for review; in cases of malignancy it will frequently indicate the presence of invasion; and, for calcifications, it may demonstrate visual target removal. However, the procedure may be more traumatic than FNAB and requires more post-procedure vigilance. With incisional image-guided biopsy procedures, one must pay attention to what is present behind the target by using some automated core devices to insure that inadvertent puncture of the pleura or pectoralis muscle does not occur, or that there is adequate breast tissue behind the mass to prevent impingement of the needle onto the cassette with stereotactic guidance. Fine-needle aspiration biopsy technique requires a trained cytopathologist. The report of a multi-center randomized trial demonstrated a 10%-11% insufficiency rate for US-guided FNAB and up to 39% for stereotactically guided procedures. The overall accuracy for US-guided FNAB was 77%, while for stereotactically guided FNAB, accuracy was only 58%. There were also 9% false positive exams, which could lead to unnecessary treatment. Unlike FNAB, core biopsy allows accurate distinction between in situ and invasive carcinoma.

Abbreviations

• CT, computed tomography
• FNAB, fine needle aspiration biopsy
• INV, invasive
• MRI, magnetic resonance imaging
• NUC, nuclear medicine
• US, ultrasound

Algorithms were not developed from criteria guidelines.

The recommendations are based on analysis of the current literature and expert panel consensus.

• D'Orsi CJ, Bassett LW, Berg WA, Bohm-Velez M, Evans WP III, Farria DM, Lee C, Mendelson EB, Goldstein S. Nonpalpable breast masses. [online publication]. Reston (VA): American College of Radiology (ACR); 2005. 12 p. [25 references]

Not applicable: The guideline was not adapted from another source.

1995 (revised 2005)

American College of Radiology - Medical Specialty Society

The American College of Radiology (ACR) provided the funding and the resources for these ACR Appropriateness Criteria®.

Committee on Appropriateness Criteria, Expert Panel on Women's Imaging--Breast Work Group

Panel Members: Carl J. D'Orsi, MD; Lawrence W. Bassett, MD; Wendie A. Berg, MD, PhD; Marcela Bohm-Velez, MD; W. Phil Evans III, MD; Dione Marie Farria, MD, MPH; Carol Lee, MD; Ellen B. Mendelson, MD; Steven Goldstein, MD

Not stated

This is the current release of the guideline.

It updates a previously published version: D'Orsi C, Mendelson E, Bassett L, Bohm-Velez M, Cardenosa G, Evans WP 3rd, Monsees B, Thurmond A, Goldstein S. Work-up of nonpalpable breast masses. American College of Radiology. ACR Appropriateness Criteria. Radiology 2000 Jun;215 Suppl:965-72.

The appropriateness criteria are reviewed annually and updated by the panels as needed, depending on introduction of new and highly significant scientific evidence.

None available

This NGC summary was completed by ECRI on February 13, 2006.