Laura Liberman

Breast Imaging Reporting and Data System (BI-RADS)

The Breast Imaging Reporting and Data System (BI-RADS) lexicon was developed by the American College of Radiology to standardize mammographic reporting. The BI-RADS lexicon defines terms to describe abnormalities on mammograms, and it defines final assessment categories that are predictive of the likelihood of malignancy. Although the lexicon is clinically useful and facilitates communication and research, there is still substantial interobserver variability in its application. Lexicons for breast sonography and breast MRI are in progress.

Sentinel lymph node biopsy: is it indicated in patients with high-risk ductal carcinoma-in-situ and ductal carcinoma-in-situ with microinvasion?

Background: Axillary lymph node status is the strongest prognostic indicator of survival for women with breast cancer. The purpose of this study was to determine the incidence of sentinel node metastases in patients with high-risk ductal carcinoma-in-situ (DCIS) and DCIS with microinvasion (DCISM).Methods: From November 1997 to November 1999, all patients who underwent sentinel node biopsy for high-risk DCIS (n = 76) or DCISM (n = 31) were enrolled prospectively in our database. Patients with DCIS were considered high risk and were selected for sentinel lymph node biopsy if there was concern that an invasive component would be identified in the specimen obtained during the definitive surgery. Patients underwent intraoperative mapping that used both blue dye and radionuclide. Excised sentinel nodes were serially sectioned and were examined by hematoxylin and eosin and by immunohistochemistry.Results: Of 76 patients with high-risk DCIS, 9 (12%) had positive sentinel nodes; 7 of 9 patients were positive for micrometastases only. Of 31 patients with DCISM, 3 (10%) had positive sentinel nodes; 2 of 3 were positive for micrometastases only. Six of nine patients with DCIS and three of three with DCISM and positive sentinel nodes had completion axillary dissection; one patient with DCIS had an additional positive node detected by conventional histological analysis.Conclusions: This study documents a high incidence of lymph node micrometastases as detected by sentinel node biopsy in patients with high-risk DCIS and DCISM. Although the biological significance of breast cancer micrometastases remains unclear at this time, these findings suggest that sentinel node biopsy should be considered in patients with high-risk DCIS and DCISM.

CLINICAL MANAGEMENT ISSUES IN PERCUTANEOUS CORE BREAST BIOPSY

Percutaneous imaging-guided core biopsy is a less invasive and less expensive alternative to surgical biopsy for the evaluation of breast lesions. Percutaneous core biopsy is most often used for evaluation of BI-RADS category 4 lesions, but may also be helpful in the evaluation of some BI-RADS category 5 lesions. Stereotactic guidance is particularly useful for calcifications; for masses that can be seen with ultrasound, ultrasound guidance may be preferable because of the absence of radiation and lower cost. The automated core biopsy needle is excellent for mass lesions, but directional vacuum-assisted biopsy is superior for calcifications. Directional vacuum-assisted biopsy may also be preferable for small lesions that may require placement of a localizing clip and lesions that are superficial or in thin breasts. The more expensive ABBI device has substantial limitations, and its role in percutaneous breast biopsy has not been demonstrated. Complete removal of the mammographic target can occur at percutaneous biopsy, and is a more frequent event when the larger tissue acquisition devices are used. Complete removal of the mammographic target does not ensure complete excision of the histologic process. Further investigation is necessary to determine in which lesions, if any, complete removal of the target is advantageous. Epithelial displacement can occur during all breast needling procedures, but may be less frequent at directional vacuum-assisted biopsy than at fine-needle aspiration or automated core biopsy. There is no evidence that displaced cells are of biologic significance, but displaced DCIS can mimic infiltrating carcinoma. The pathologist should be aware of the findings of epithelial displacement, to avoid misdiagnosing DCIS as infiltrating ductal carcinoma. Some lesions warrant repeat biopsy or surgical excision after percutaneous core biopsy. Repeat biopsy is warranted if histologic findings and imaging findings are discordant. Surgical excision is warranted for lesions yielding a percutaneous diagnosis of ADH or possible phyllodes tumor. Controversy exists regarding the need for surgical excision after percutaneous diagnosis of radial scar, papillary lesion, ALH, or LCIS. Follow-up is necessary if percutaneous biopsy yields benign findings concordant with imaging characteristics. Follow-up protocols vary, but all require substantial commitment of time and resources. We have an embarassment of riches for performing percutaneous core biopsy of the breast. It can be estimated that approximately 1 million breast biopsies will be performed this year to diagnose approximately 200,000 breast cancers. Percutaneous core biopsy may spare many of these women the need for a more deforming, invasive, and expensive surgical biopsy. Further work is necessary to optimize criteria for patient selection, develop and define the role of new technologies for tissue acquisition, refine protocols for management after percutaneous breast biopsy, and assess long-term outcome, so that more women can benefit from this minimally invasive approach to breast diagnosis.

Determination of the presence and extent of pure ductal carcinoma in situ by mammography and magnetic resonance imaging.

Abstract:  The purpose of this study was to compare the ability of magnetic resonance imaging (MRI) and mammography to determine the presence and extent of ductal carcinoma in situ (DCIS). Retrospective review of medical records of women who underwent MRI and mammographic examination during a 23‐month period revealed 39 sites of pure DCIS in 33 breasts of 32 women. No invasive or microinvasive tumor was found. Women ranged in age from 34 to 79 years (mean age 53 years). In these 33 breasts, both MRI and mammography were done before surgery. Reports and images of mammography and MRI were reviewed to determine if each study was positive for the presence of single or multiple sites of DCIS and the imaging patterns associated with these sites. Of 33 breasts involved, DCIS was discovered by MRI alone in 21 (64%), by both MRI and mammography in 8 (24%), and by mammography alone in 1 (3%); in 3 breasts (9%), DCIS was found at mastectomy without findings on mammography or MRI. MRI had significantly higher sensitivity than mammography for DCIS detection (29/33 = 88% versus 9/33 = 27%, p < 0.00001). Multiple sites of disease were present in five breasts; these were better demonstrated with MRI in three, mammography in one, and equally by both in one. The predominant enhancement pattern of DCIS on MRI was linear/ductal in 18 of 29 breasts (62%); mammography found calcifications associated with DCIS in 8 of 9 (89%). The nuclear grade of DCIS found with MRI and mammography was similar; size of lesions was larger on MRI; breast density did not impact results. In this study, MRI was significantly more sensitive than mammography in DCIS detection. In women with known or suspected DCIS, MRI may have an important role to play in assessing the extent of disease in the breast.

Does Size Matter? Positive Predictive Value of MRI-Detected Breast Lesions as a Function of Lesion Size

OBJECTIVE The purpose of this study was to determine the impact of lesion size on the positive predictive value (PPV) of biopsy in MRI-detected breast lesions. MATERIALS AND METHODS A retrospective review was performed of 666 consecutive nonpalpable, mammographically occult lesions that had MRI-guided localization. MRI examinations were performed using a 1.5-T magnet. Lesions were measured by the interpreting radiologist before biopsy. Malignancy rate versus lesion size was determined. RESULTS The median MRI lesion size was 1 cm (range, 0.3-7.0 cm). Malignancy was present in 149/666 (22%) lesions, of which 80 (54%) were ductal carcinoma in situ (DCIS), 66 (44%) were invasive cancer, and three (2%) were lymphoma. The frequency of malignancy increased significantly (p = 0.0005) with lesion size, with malignancy found in one (3%) of 37 lesions less than 5 mm, 44 (17%) of 254 lesions 5-9 mm, 37 (25%) of 151 lesions 10-14 mm, 21 (28%) of 74 lesions 15-19 mm, and 46 (31%) of 150 lesions 20 mm or larger. Lesions less than 5 mm accounted for 37 (6%) of 666 lesions that had a biopsy and one (< 1%) of 149 cancers (one DCIS). Among lesions less than 10 mm, the likelihood of malignancy was highest in postmenopausal women (22% malignant) and in the extent of disease setting (22% malignant), and lowest in premenopausal women (10% malignant) and in the high-risk screening setting (10% malignant). CONCLUSION The PPV of biopsy for lesions identified at breast MRI using a 1.5-T magnet significantly increased with increasing lesion size. Biopsy is rarely necessary for lesions smaller than 5 mm because of their low (3%) likelihood of cancer. Further work is needed to develop an algorithm that uses size in addition to other patient and lesion factors to guide biopsy recommendations for MRI-detected breast lesions.

Percutaneous image-guided core breast biopsy

Percutaneous image-guided core biopsy is an accurate, fast, minimally invasive, and less expensive alternative to surgery for the diagnosis of breast lesions. Percutaneous core biopsy is usually performed under stereotactic or ultrasound guidance, using an automated needle or vacuum-assisted biopsy probe. Use of percutaneous core biopsy spares the need for surgery in most women with benign disease and expedites treatment in women with breast cancer. This article reviews advantages, limitations, controversies, and future directions in percutaneous image-guided core breast biopsy.

US-guided 14-gauge Core-Needle Breast Biopsy: Results of a Validation Study in 1352 Cases

PURPOSE To retrospectively determine the false-negative rate and the underestimation rate of ultrasonography (US)-guided 14-gauge core-needle breast biopsy (CNB) in nonpalpable lesions, with validation at surgical excision histologic examination and with stability during clinical and imaging follow-up. MATERIALS AND METHODS Informed consent was waived by the institutional review board for this retrospective review of 1352 cases. In 1061 cases, patients underwent surgical excision of lesions visible at US subsequent to US-guided 14-gauge CNB. Follow-up of another 291 benign lesions at US-guided 14-gauge CNB histologic examination showed stability during clinical and imaging follow-up for at least 2 years. US and histologic findings were reviewed and compared for agreement. A false-negative finding was defined as pathologically proved cancer for which biopsy results were benign. The false-negative rate was defined as the proportion of all breast cancers with a diagnosis of benign disease at US-guided 14-gauge CNB. The underestimation rate was defined as an upgrade of a high-risk lesion at US-guided 14-gauge CNB to malignancy at surgery. RESULTS US 14-gauge CNB yielded 671 (63.2%) malignant, 86 (8.1%) high-risk, and 304 (28.7%) benign lesions. Each of the 291 benign lesions without surgery remained stable during follow-up. The agreement of US-guided 14-gauge CNB results, surgical excision findings, and follow-up results was 95.8% (kappa = 0.93). False-negative findings were encountered in 11 (0.8%) of 1352 cases, and the false-negative rate was 1.6% (11 of 671 malignancies). All false-negative findings were prospectively identified owing to discordance between imaging results and US-guided 14-gauge CNB histologic findings. The underestimation rate was 31.4%. CONCLUSION US-guided 14-gauge CNB is an alternative to surgical excision for assessing nonpalpable breast lesions.

Underestimation of Atypical Ductal Hyperplasia at MRI-Guided 9-Gauge Vacuum-Assisted Breast Biopsy

OBJECTIVE The purposes of this study were to determine the frequency of diagnosis of atypical ductal hyperplasia (ADH) at MRI-guided 9-gauge vacuum-assisted breast biopsy and to assess the rate of underestimation of ADH at subsequent surgical excision. MATERIALS AND METHODS We conducted a retrospective review of medical records of 237 lesions consecutively detected with MRI and then subjected to MRI-guided 9-gauge vacuum-assisted breast biopsy during a 33-month period. Underestimated ADH was defined as a lesion yielding ADH at vacuum-assisted biopsy and cancer at surgery. Scientific tables were used to calculate 95% CI. RESULTS Histologic analysis of MRI-guided vacuum-assisted breast biopsy specimens yielded ADH without cancer in 15 (6%) of 237 lesions. Among 15 patients in whom vacuum-assisted breast biopsy yielded ADH, the median age was 52 years (range, 46-68 years). The median number of specimens obtained was nine (range, 8-18 lesions). Median MRI lesion diameter was 1.3 cm (range, 0.7-7.0 cm). Among 15 MRI lesions, 10 (67%) were nonmasslike enhancement and five (33%) were masses. Surgical excision was performed on 13 lesions. Surgical histologic findings were malignancy in five (38%) of the cases, all ductal carcinoma in situ; high-risk lesion in six (46%) of the cases, including ADH without other high-risk lesions (n = 2), ADH and lobular carcinoma in situ (LCIS) (n = 1), ADH, LCIS, and papilloma (n =1), ADH and papilloma (n = 1), and LCIS (n = 1); and benign in two (15%) of the cases. These data indicated an ADH underestimation rate of 38% (95% CI, 14-68%). CONCLUSION ADH without cancer was encountered in 6% of MRI-guided 9-gauge vacuum-assisted breast biopsies. ADH at MRI-guided vacuum-assisted breast biopsy is an indication for surgical excision because of the high (38%) frequency of underestimation of these lesions.

Probably Benign Lesions at Breast Magnetic Resonance Imaging Preliminary Experience in High-Risk Women

The purpose of the current study was to determine the frequency of ‘probably benign’ interpretations at breast magnetic resonance (MR) imaging screening of high‐risk women and the frequency of subsequent malignancy in these women.

Breast MRI Screening of Women With a Personal History of Breast Cancer

OBJECTIVE The purpose of this article is to determine the cancer detection and biopsy rate among women who have breast MRI screening solely on the basis of a personal history of breast cancer. MATERIALS AND METHODS This retrospective review of 1,699 breast MRI examinations performed from 1999 to 2001 yielded 144 women with prior breast cancer but no family history who commenced breast MRI screening during that time. Minimal breast cancer was defined as ductal carcinoma in situ (DCIS) or node-negative invasive breast cancer < 1 cm in size. RESULTS Of 144 women, 44 (31% [95% CI, 15-29%]) underwent biopsies prompted by MRI examination. Biopsies revealed malignancies in 17 women (12% [95% CI, 7-18%]) and benign findings only in 27 women (19% [95% CI, 13-26%]). Of the 17 women in whom cancer was detected, seven also had benign biopsy results. In total, 18 malignancies were found. One woman had two metachronous cancers. MRI screening resulted in a total of 61 biopsies, with a positive predictive value (PPV) of 39% (95% CI, 27-53%). The malignancies found included 17 carcinomas and one myxoid liposarcoma. Of the 17 cancers, 12 (71%) were invasive, five (29%) were DCIS, and 10 (59%) were minimal breast cancers. Of 17 cancers, 10 were detected by MRI only. The 10 cancers detected by MRI only, versus seven cancers later found by other means, were more likely to be DCIS (4/10 [40%] vs 1/7 [14%]; p = 0.25) or minimal breast cancers (7/10 [70%] vs 3/7 [43%]; p = 0.26). CONCLUSION We found that breast MRI screening of women with only a personal history of breast cancer was clinically valuable finding malignancies in 12%, with a reasonable biopsy rate (PPV, 39%).