Observer variability and applicability of BI-RADS terminology for breast MR imaging: invasive carcinomas as focal masses.

OBJECTIVE: The purpose of this study was to assess whether the descriptive terminology and final assessment categories of the Breast Imaging Reporting and Data System (BI-RADS) lexicon can be used for breast carcinomas detected on MR imaging and to assess the inter- and intraobserver variabilities in the use of the descriptors and final assessment categories. MATERIALS AND METHODS: In 82 patients, 101 masses, including 68 infiltrating carcinomas and 33 benign lesions, were interpreted independently by four radiologists and described by BI-RADS terminology with respect to mass shape and margin and BI-RADS final assessment categories. The enhancement pattern of the mass was also reported. In addition, two radiologists interpreted each case twice to evaluate intraobserver variability. The final case set for analysis was the 68 infiltrating carcinomas. RESULTS: Most of the infiltrating carcinomas were described as irregular, spiculated, and heterogeneously enhancing masses. The final impression of the 68 carcinomas was BI-RADS category 5 (highly suggestive of malignancy) in 41 (61%), category 4 (suspicious abnormality) in 24 (35%), and category 3 (probably benign) in three (4%). Enhancement pattern was heterogeneous in 40 (59%), homogeneous in 14 (21%), and rim in 14 (21%). Interobserver agreement was moderate for mass margin, shape, enhancement, and final assessment category. CONCLUSION: This study suggests that the mammographic BI-RADS lexicon with some modifications may be applied to describe the features of infiltrating carcinoma seen on breast MR imaging.

Bracketing wires for preoperative breast needle localization.

OBJECTIVE: The purpose of this study was to evaluate the outcomes of bracketing wire placement during preoperative breast needle localization. SUBJECTS AND METHODS: We prospectively examined mammograms of 1057 consecutive lesions that had preoperative needle localization and surgical excision and classified the lesions according to Breast Imaging Reporting and Data System (BI-RADS) final assessment categories. Bracketing wires, defined as multiple wires placed to delineate the boundaries of a single lesion, were used in 103 (9.7%) of 1057 lesions. Medical records, imaging studies, and histologic findings in these 103 lesions were reviewed. RESULTS: Of 103 bracketed lesions, median lesion size was 3.5 cm (range, 1.5-9.5 cm). Ninety-three lesions (90.3%) contained calcifications; 65 lesions (63.1%) were BI-RADS category 5 (highly suggestive of malignancy); and 33 lesions (32.0%) were percutaneously proven cancers. The median number of wires placed was two (range, 2-5). Surgical histologic findings were carcinoma in 75 lesions (72.8%), atypical hyperplasia in eight lesions (7.8%), and benign in 20 lesions (19.4%). Of 42 calcific lesions that were bracketed and had postoperative mammograms available for review, complete removal of suspicious calcifications was accomplished in 34 (81.0%). Of 75 cancers that were bracketed, clear histologic margins of resection were obtained in 33 (44.0%). CONCLUSION: Bracketing wires were used during preoperative needle localization primarily for larger calcific lesions that were proven cancers or were highly suggestive of malignancy (BI-RADS category 5). Bracketing wires may assist the surgeon in achieving complete excision of calcifications, but bracketing wires do not ensure clear histologic margins of resection.

Calcifications highly suggestive of malignancy: comparison of breast biopsy methods.

OBJECTIVE: The purpose of this study was to compare the usefulness of, and cost of diagnosing with, different breast biopsy methods for women with calcifications highly suggestive of malignancy. MATERIALS AND METHODS: One hundred thirty-nine women with calcifications highly suggestive of malignancy underwent diagnostic biopsy. Of these, 89 women had stereotactic biopsy with a 14-gauge automated needle (n = 25), 14-gauge vacuum-assisted probe (n = 17), or 11-gauge vacuum-assisted probe (n = 47); and 50 women had diagnostic surgical biopsy. Medical records were reviewed. Cost savings for stereotactic biopsy were calculated using Medicare data. RESULTS: The median number of operations was one for women who had stereotactic biopsy versus two for women who had diagnostic surgical biopsy. The likelihood of undergoing a single operation was significantly greater for women who had stereotactic rather than surgical biopsy, among all women (61/89 [68.5%] vs. 19/50 [38.0%], p < 0.001) and among women treated for breast cancer (55/77 [71.4%] vs. 6/37 [16.2%], p = 0.0000001). Stereotactic 11-gauge vacuum-assisted biopsy, as compared with 14-gauge automated core or 14-gauge vacuum-assisted biopsy, was significantly more likely to spare a surgical procedure (36/47 [76.6%] vs. 16/42 [38.1%], p = 0.0005). Stereotactic 11-gauge vacuum-assisted biopsy resulted in the greatest cost reduction, yielding savings of $315 per case compared with diagnostic surgical biopsy; for women with solitary lesions, stereotactic 11-gauge biopsy decreased the cost of diagnosis by 22.2% ($334/$1502). CONCLUSION: For women with calcifications highly suggestive of malignancy, the use of stereotactic rather than surgical biopsy decreases the number of operations. Stereotactic 11-gauge vacuum-assisted biopsy, as compared with 14-gauge automated core or 14-gauge vacuum-assisted biopsy, is significantly more likely to spare a surgical procedure and has the highest cost savings.

Stereotactic core-needle breast biopsy: a multi-institutional prospective trial.

PURPOSE: To assess the accuracy of stereotactic core-needle biopsy (CNB) of nonpalpable breast lesions within the context of clinically important parameters of anticipated tissue-sampling error and concordance with mammographic findings. MATERIALS AND METHODS: CNB was performed in 1,003 patients, with results validated at surgery or clinical and mammographic follow-up. Mammographic findings were scored according to the American College of Radiology Breast Imaging Reporting and Data System with a similar correlative scale for histopathologic samples obtained at either CNB or surgery. Agreement of CNB findings with surgical findings or evidence of no change during clinical and mammographic follow-up (median, 24 months) for benign lesions was used to determine results. Three forms of diagnostic discrimination measures (strict, working [strict conditioned by tissue sampling error], applied [working conditioned by concordance of imaging and CNB findings) were used to evaluate the correlation of CNB, surgical, and follow-up results. RESULTS: Strict, working, and applied sensitivities were 91% +/- 1.9; 92% +/- 1.8, and 98% +/- 0.9, respectively; strict, working, and applied specificities were 100%, 98% +/- 0.8, and 73% +/- 0.9; strict, working, and applied accuracies were 97%, 96%, and 79%. CONCLUSION: Percutaneous stereotactic CNB is an accurate method to establish a histopathologic diagnosis of nonpalpable breast lesions. Accuracy increases when additional surgery is performed for lesions with anticipated sampling error or when CNB findings are discordant with mammographic findings. An understanding of the interrelationship among these parameters is necessary to properly assess results.

Learning curve for stereotactic breast biopsy: how many cases are enough?

OBJECTIVE: The objective of this study was to evaluate the learning curve for stereotactic breast biopsy. MATERIALS AND METHODS: Retrospective review was performed of 923 consecutive lesions that underwent stereotactic breast biopsy performed by one of six radiologists. Four hundred fourteen lesions had 14-gauge automated core biopsy, and 509 subsequent lesions had vacuum-assisted biopsy (14-gauge in 163 and 11-gauge in 346). Medical records were reviewed to determine the technical success rate and false-negative rate as a function of operator experience. RESULTS: For 14-gauge automated core biopsy, a significantly lower technical success rate was seen for the first five cases of each radiologist than for subsequent cases (25/30 = 83.3% versus 366/384 = 95.3%, p < 0.02) and for the first 20 cases than for subsequent cases (90/100 = 90% versus 284/296 = 95.9%, p < 0.05). For 11-gauge vacuum-assisted biopsy, a significantly lower technical success rate was seen for the first five cases than for subsequent cases (17/20 = 85.0% versus 310/322 = 96.3%, p < 0.05) and for the first 15 cases than for subsequent cases (54/60 = 90.0% versus 273/283 = 96.5%, p = 0.03). The false-negative rate was higher for the first 15 cases compared with subsequent cases both for stereotactic 14-gauge automated core biopsy (4/31 = 12.9% versus 3/115 = 2.6%, p < 0.04) and for stereotactic 11-gauge vacuum-assisted biopsy (2/27 = 7.4% versus 0/85 = 0%, p < 0.06). CONCLUSION: A learning curve exists for stereotactic breast biopsy. Significantly higher technical success rates and lower false-negative rates were observed after the first five to 20 cases for 14-gauge automated core biopsy and after the first five to 15 cases for 11-gauge vacuum-assisted biopsy. Even after a radiologist has experience with stereotactic biopsy, changes in equipment may result in a new learning curve.

Mammographic screening of the high-risk woman.

Annual screening mammography beginning at age 40 is recommended for the general population. For some women at high risk for developing breast cancer at a younger age, annual screening may be appropriate starting at an earlier age. These women include those with a personal history of breast cancer, nontherapeutic radiation to the breasts especially for Hodgkin's disease, BRCA positive women, women with a family history of a first-degree relative with breast cancer at a young age, and women with a biopsy diagnosis of lobular carcinoma in situ or atypical ductal hyperplasia. Women with a biopsy diagnosis of atypical lobular hyperplasia develop breast cancer after age 40 and do not need earlier screening, unless they have a family history of breast cancer. Although increasing a woman's risk for breast cancer, radial scar does not increase risk for women younger than 40 years old and therefore does not require screening at a young age.

Palpable breast masses: is there a role for percutaneous imaging-guided core biopsy?

OBJECTIVE: The purpose of this study was to evaluate percutaneous imaging-guided core biopsy in the assessment of selected palpable breast masses. MATERIALS AND METHODS: Of 1388 consecutive breast lesions that had percutaneous imaging-guided core biopsy, 155 (11%) were palpable. Palpable masses referred for percutaneous imaging-guided core biopsy included lesions that were small, deep, mobile, vaguely palpable, or multiple. Biopsy guidance was sonography in 140 lesions (90%) and stereotaxis in 15 (10%). Surgical correlation or minimum of 2 years follow-up is available in 115 palpable masses in 107 women. Medical records, imaging studies, and histologic findings were reviewed. RESULTS: Of 115 palpable breast masses, 98 (85%) were referred by surgeons to the radiology department for percutaneous imaging-guided core biopsy and 88 (77%) had percutaneous imaging-guided core biopsy on the day of initial evaluation at our institution. Percutaneous imaging-guided core biopsy spared additional diagnostic tissue sampling in 79 (74%) of 107 women, including 57 women with carcinoma and 22 women with benign findings. Percutaneous imaging-guided core biopsy did not spare additional tissue sampling in 28 women (26%), including 15 women in whom surgical biopsy was recommended on the basis of percutaneous biopsy findings and 13 women with benign (n = 7) or malignant (n = 6) percutaneous biopsy findings who chose to undergo diagnostic surgical biopsy. CONCLUSION: Percutaneous imaging-guided core biopsy is useful in the evaluation of palpable breast masses that are small, deep, mobile, vaguely palpable, or multiple. In this study, percutaneous imaging-guided core biopsy spared additional diagnostic tissue sampling in 74% women with palpable breast masses.

Equipment, technique, quality assurance, and accreditation for imaging-guided breast biopsy procedures.

Needle biopsy diagnosis of breast lesions can be performed using fine needle aspiration or large core needle biopsy techniques. Imaging guidance using mammographic stereotactic devices or sonography can accurately guide biopsy probes into suspicious lesions. Choice of the biopsy probe in any individual patient will depend upon equipment availability, lesion characteristics, breast configuration, and cost considerations. Quality control and quality assurance programs should be instituted to maintain a high level of patient care. Facilities performing these biopsies can obtain accreditation to attest to the quality of their biopsy program.

Evaluation of pectoralis major muscle in patients with posterior breast tumors on breast MR images: early experience.

PURPOSE: To evaluate the ability to use breast magnetic resonance (MR) imaging to assess disease extent in patients with posterior breast masses who are suspected to have tumor invasion into underlying muscle. MATERIALS AND METHODS: Nineteen patients with posterior breast masses underwent three-dimensional, gradient-echo, 1.5-T MR imaging before and after the administration of gadopentetate dimeglumine. Thirteen had deep palpable masses that were clinically determined to be fixed to the underlying chest wall. Twelve had mammographic findings that caused muscle involvement to be suspected, and seven had normal mammograms. All patients underwent surgery. MR images were reviewed and were correlated with histologic findings. RESULTS: Enhancing masses were identified on MR images in all 19 patients. Five (26%) of the 19 patients had masses that abutted the muscles, with obliteration of the fat plane and muscle enhancement. All five had muscle involvement at surgery. In the remaining 14 (74%) patients, no enhancement of muscle was seen; none of these had invasion of the muscle at surgery. CONCLUSION: Extension of adjacent tumor into underlying musculature was indicated by abnormal enhancement within these structures. Violation of the fat plane between tumor and muscle, without other findings, did not indicate tumor involvement of these deep structures.

Imaging-histologic discordance at percutaneous breast biopsy.

BACKGROUND: The purpose of the current study was to determine the frequency of imaging-histologic discordance at percutaneous breast biopsy and to assess the likelihood of carcinoma in these discordant lesions. METHODS: Percutaneous imaging guided breast biopsy was performed on 1785 consecutive lesions during a 7-year period under stereotactic (n = 1205) or sonographic (n = 580) guidance, using an automated needle (n = 1044) or directional vacuum-assisted probe (n = 741). Lesions were prospectively classified according to the Breast Imaging Reporting and Data System (BI-RADS) as Category 3 (probably benign), Category 4 (suspicious), or Category 5 (highly suggestive of malignancy). Imaging-histologic discordance was considered to have occurred when the percutaneous biopsy histology did not provide a sufficient explanation for the imaging features; in such cases, repeat biopsy was recommended. Medical records, imaging studies, and histologic findings were reviewed. RESULTS: Imaging-histologic discordance was present in 56 of 1785 (3.1%) lesions. The frequency of discordance was significantly higher in our first 2 years of experience with percutaneous biopsy than in later years (18 of 361 = 5.0% vs. 38 of 1424 = 2.7%; P < 0.04) and was significantly higher for lesions that were BI-RADS Category 5 rather than BI-RADS Category 4 (20 of 416 = 4.8% vs. 36 of 1366 = 2. 6%; P < 0.04). The frequency of discordance was significantly lower with the 11-gauge vacuum-assisted probe than other devices for calcifications (7 of 414 = 1.7% vs. 16 of 251 = 6.8%; P = 0.001) but not for masses (6 of 161 = 3.7% vs. 26 of 959 = 2.7%; P = 0.44). Repeat biopsy, performed in 45 discordant lesions revealed carcinoma in 11 (24.4%; 95% confidence intervals, 12.9-39.5%). The frequency of carcinoma was significantly higher among discordant BI-RADS Category 5 than discordant BI-RADS Category 4 lesions (7 of 16 = 43. 8% vs. 4 of 29 = 13.7%; P < 0.04). CONCLUSIONS: Imaging-histologic discordance occurred in 3.1% of lesions that had percutaneous breast biopsy. Imaging-histologic discordance was an indication for surgical excision because of the high (24.4%) prevalence of carcinoma in these lesions.

Complete percutaneous excision of infiltrating carcinoma at stereotactic breast biopsy: how can tumor size be assessed?

OBJECTIVE: The purpose of this study was to determine the frequency of complete excision of infiltrating carcinoma at stereotactic 11-gauge directional vacuum-assisted breast biopsy and to evaluate the feasibility of measuring tumor size in stereotactic biopsy specimens in infiltrating carcinomas that were percutaneously excised. MATERIALS AND METHODS: We performed retrospective review of 51 infiltrating carcinomas diagnosed using stereotactic 11-gauge directional vacuum-assisted biopsy that underwent subsequent surgery. For lesions yielding no residual infiltrating carcinoma at surgery, the maximal dimension of the tumor was measured in stereotactic biopsy specimens using ocular micrometry. RESULTS: In 10 (20%) (95% confidence intervals, 9.8-33.1%) of 51 infiltrating carcinomas diagnosed at stereotactic biopsy, surgery revealed no residual infiltrating carcinoma. Complete excision of infiltrating carcinoma was more frequent if 14 or more specimens were obtained (32% versus 0%, p < .004), if the mammographic lesion was removed (35% versus 7%, p < .03), and if the mammographic lesion size measured 0.7 cm or less (50% versus 16%, p = .08). Tumor size in stereotactic biopsy specimens was within 3 mm of mammographic lesion size in six (60%) of 10 lesions, including five (71%) of seven masses and one (33%) of three calcification lesions, but was smaller than the mammographic lesion size in eight (80%) of 10 lesions. CONCLUSION: Surgery revealed no residual infiltrating carcinoma in 10 (20%) of 51 infiltrating carcinomas diagnosed at stereotactic 11-gauge biopsy. Although tumor size can be assessed in stereotactic biopsy specimens in these lesions, such measurements may underestimate the maximal dimension of the tumor. Further study is needed to evaluate the usefulness of these measurements in guiding treatment decisions.

Lobular carcinoma in situ at percutaneous breast biopsy: surgical biopsy findings.

OBJECTIVE: The purpose of this study was to review surgical histologic findings in women with lobular carcinoma in situ (LCIS) at percutaneous breast biopsy. MATERIALS AND METHODS: Retrospective review was performed of 1315 consecutive lesions that underwent percutaneous breast biopsy. Percutaneous biopsy yielded LCIS in 16 (1.2%) lesions. Subsequent surgical biopsy was performed in 14 lesions in 13 women. Histologic findings were reviewed. RESULTS: In five of the 14 lesions, percutaneous biopsy yielded LCIS and a high-risk lesion (radial scar in three and atypical ductal hyperplasia in two); in one (20%) of these five lesions, surgery revealed ductal carcinoma in situ (DCIS). In four of the 14 lesions, the LCIS in the percutaneous biopsy had features that overlapped with those of DCIS; in two (50%) of these four lesions, surgery revealed DCIS (n = 1) or infiltrating lobular carcinoma (n = 1). In the remaining five of the 14 lesions, surgery revealed no DCIS or infiltrating carcinoma. Five (38%) of 13 women with LCIS lesions had synchronous or metachronous infiltrating carcinoma (three ductal, one lobular, one mixed) in the ipsilateral (n = 1) or contralateral (n = 4) breast. CONCLUSION: Surgical excision was warranted in lesions in which LCIS was found at percutaneous breast biopsy when the percutaneous biopsy histologic features overlapped with those of DCIS, when a high-risk lesion was present, or when there was imaging-histologic discordance. LCIS without these factors was not shown to require surgical excision in our small series, but a larger study is needed. Diagnosis of LCIS at percutaneous biopsy is a marker for women who are at increased risk of ductal or lobular carcinoma in either breast.

Sentinel lymph node biopsy after percutaneous diagnosis of nonpalpable breast cancer.

PURPOSE: To determine the technical success rate of sentinel lymph node biopsy in women with nonpalpable infiltrating breast cancer diagnosed by using percutaneous core biopsy and to determine the frequency with which sentinel lymph node biopsy obviated axillary dissection. MATERIALS AND METHODS: Retrospective review revealed 33 women who underwent sentinel node biopsy after percutaneous core biopsy diagnosis of nonpalpable infiltrating breast cancer. Sentinel nodes were identified with radioisotope and blue dye; the procedure was technically successful if sentinel nodes were found at surgery. All sentinel nodes were excised. Axillary dissection was performed if tumor was present in sentinel nodes. RESULTS: Sentinel nodes were found at surgery in 30 women (91%). Sentinel nodes were identified with both radioisotope and blue dye in 22 (73%) of these women, with only radioisotope in six (20%), and with only blue dye in two (7%). Sentinel nodes were found in 12 (80%) of 15 women in the first half of the study versus all 18 (100%) women in the second half (P = .08). Sentinel nodes were free of tumor in 23 (77%) of 30 women. In six (86%) of seven women with tumor in sentinel nodes, the sentinel nodes were the only nodes with tumor. CONCLUSION: Sentinel node biopsy was successful in 30 women (91%) with nonpalpable infiltrating carcinoma diagnosed with percutaneous core biopsy and obviated axillary dissection in 23 women (70%). Using both radioisotope and blue dye may increase the success rate. A learning curve exists, and success improves with experience.

Epithelial displacement after stereotactic 11-gauge directional vacuum-assisted breast biopsy.

OBJECTIVE: Displaced epithelial fragments at percutaneous biopsy of ductal carcinoma in situ (DCIS) may mimic stromal invasion. This study was undertaken to determine the frequency of epithelial displacement in DCIS lesions of patients who underwent stereotactic 11-gauge directional vacuum-assisted breast biopsy. MATERIALS AND METHODS: We retrospectively reviewed 28 consecutive DCIS lesions in patients who underwent stereotactic 11-gauge directional vacuum-assisted breast biopsy followed by surgery. Surgical specimens were examined for histologic evidence of epithelial displacement, consisting of fragments of epithelium in artifactual spaces in breast parenchyma or in lymphovascular channels, accompanied by hemorrhage, fat necrosis, inflammation, hemosiderin-laden macrophages, or granulation tissue. RESULTS: The median number of specimens obtained per lesion was 14 (range, seven to 45). The median interval from stereotactic biopsy to surgery was 27 days (range, 10-59 days). Surgery revealed DCIS in 19 (68%) of 28 lesions, DCIS and infiltrating carcinoma in four lesions (14%), and no residual carcinoma in five lesions (18%). Reactive changes at the biopsy site were identified in all cases. Displacement of benign epithelium into granulation tissue at the stereotactic biopsy site was identified in two cases (7%). We found no evidence of displacement of malignant epithelium. CONCLUSION: Epithelial displacement is uncommon after stereotactic 11-gauge directional vacuum-assisted biopsy of the breast. We observed displacement of benign epithelium in two (7%) of 28 DCIS lesions and no displacement of malignant epithelium.

Percutaneous large-core biopsy of papillary breast lesions.

OBJECTIVE: This study was undertaken to assess the accuracy of percutaneous large-core biopsy in evaluating papillary breast lesions. MATERIALS AND METHODS: A retrospective review of imaging-guided large-core breast biopsy of 1077 consecutive lesions revealed that papillary lesions were diagnosed in 34 (3%) cases. Surgical correlation (n = 22) or minimum 2 years' mammographic follow-up (n = 4) were available for 26 papillary lesions. Mammographic and histologic findings in these 26 cases were reviewed. RESULTS: Percutaneous biopsy histology had benign findings in nine lesions, atypical in 10, and malignant in seven. Of seven lesions yielding benign papilloma at percutaneous biopsy, none (0%) had carcinoma at surgery or mammographic follow-up. Surgery revealed carcinoma in one of two lesions yielding papillomatosis at percutaneous biopsy. This lesion was a spiculated mass; surgical biopsy, recommended because of mammographic-histologic discordance, revealed a radial sclerosing lesion and ductal carcinoma in situ (DCIS). Of 10 papillary lesions with atypical ductal hyperplasia at percutaneous biopsy, surgery revealed DCIS in three (30%). Of seven lesions in which percutaneous biopsy yielded papillary DCIS, surgery revealed DCIS in all seven; three (43%) also had invasive carcinoma. CONCLUSION: Among our patients, diagnosis by percutaneous core biopsy of benign papillary lesions proved to be accurate when concordant with imaging findings. Surgical excision was indicated when diagnosis by percutaneous biopsy revealed atypical papillary lesions or papillary DCIS. A larger series with longer follow-up is required to assess the clinical course of benign papillary lesions without atypia that are not excised after percutaneous large-core breast biopsy.

US-guided core breast biopsy: use and cost-effectiveness.

PURPOSE: To determine the frequency with which ultrasonographically (US) guided core biopsy obviated diagnostic surgical biopsy of nonpalpable breast masses, to calculate the cost savings of diagnosis attributable to US-guided core biopsy, and to compare the costs of US-guided versus stereotactically guided core biopsy. MATERIALS AND METHODS: US-guided core biopsy was performed in 151 consecutive solitary, nonpalpable breast masses in 151 women (age range, 23-80 years) by using a 14-gauge automated gun and needle. Clinical follow-up data were obtained. Cost savings were assessed by using national Medicare reimbursement costs of +385 for US-guided core biopsy, +610 for stereotactic core biopsy, and +1,332 for needle localization and surgical biopsy. RESULTS: US-guided core biopsy obviated a surgical procedure in 128 (85%) of 151 women. The mean adjusted direct cost saving per US-guided core biopsy was +744 per case. Use of US-guided biopsy decreased the cost of diagnosis by 56% (+744/+1,332) over the cost of surgical biopsy. If biopsy had been performed with stereotactic rather than with US guidance, the mean adjusted direct cost saving would have been +519 per case, a 39% (+519/1,332) decrease in the cost of diagnosis compared with the cost of surgical biopsy. CONCLUSION: Percutaneous biopsy of a nonpalpable breast mass with either US or stereotactic guidance is less expensive than surgery, but cost savings are greater with US-guided biopsy.

The breast imaging reporting and data system: positive predictive value of mammographic features and final assessment categories.

OBJECTIVE: The purpose of the study was to assess the positive predictive value of mammographic features and final assessment categories described in the Breast Imaging Reporting and Data System (BI-RADS) for lesions on which biopsies have been performed. SUBJECTS AND METHODS: We prospectively evaluated 492 impalpable mammographically detected lesions on which surgical biopsy (as opposed to percutaneous biopsy) was performed. Each lesion was classified according to BI-RADS descriptors for masses (margins and shape) and calcifications (morphology and distribution) and was categorized by the BI-RADS final assessment categories as category 3 ("probably benign"), category 4 ("suspicious abnormality"), or category 5 ("highly suggestive of malignancy"). Mammographic and pathologic findings were reviewed. RESULTS: Carcinoma was present in 225 (46%) of 492 lesions. For the 492 lesions subject to biopsy, BI-RADS final assessment categories were category 3 in eight lesions (2%), category 4 in 355 (72%), and category 5 in 129 (26%). The features with highest positive predictive value for carcinoma were spiculated margins (81%), irregular shape (73%), linear calcification morphology (81%), and segmental or linear calcification distribution (74% and 68%, respectively). Carcinoma was present in 105 (81%) of 129 category 5 lesions compared with 120 (34%) of 355 category 4 lesions (p < .001). The frequency of carcinoma was higher in category 5 than in category 4 lesions for all mammographic lesion types and all interpreting radiologists. CONCLUSION: The standardized terminology of the BI-RADS lexicon allows quantification of the likelihood of carcinoma in an impalpable breast lesion. The features with highest positive predictive value--spiculated margins, irregular shape, linear morphology, and segmental or linear distribution--warrant designation of a lesion as category 5.

Calcification retrieval at stereotactic, 11-gauge, directional, vacuum-assisted breast biopsy.

PURPOSE: To determine the frequencies of calcification retrieval and histologic underestimates at stereotactic, 11-gauge, directional, vacuum-assisted breast biopsy. MATERIALS AND METHODS: Retrospective review of records revealed 112 calcific lesions in 80 women (aged 31-85 years) who underwent stereotactic, 11-gauge, directional, vacuum-assisted biopsy; a mean of 14 specimens per lesion were obtained. Calcification retrieval was defined as identification of calcifications on radiographs of specimens. Atypical ductal hyperplasia (ADH) underestimates were lesions that yielded ADH at stereotactic biopsy and carcinoma at surgery. Ductal carcinoma in situ (DCIS) underestimates were lesions that yielded DCIS at stereotactic biopsy and infiltrating carcinoma at surgery. Mammograms, stereotactic images, radiographs of specimens, and histologic findings were reviewed. RESULTS: Stereotactic, 11-gauge, directional, vacuum-assisted biopsy removed all calcifications in 51 (46%) lesions, some calcifications in 55 (49%) lesions, and no calcifications in six (5%) lesions. Failure to retrieve calcifications was significantly more likely in lesions 5 mm or smaller (12% [five of 43] vs 1% [one of 69], P = .03), in calcifications with amorphous morphology (21% [three of 14] vs 3% [three of 98], P < .03), or if the probe was fired outside the breast (12% [five of 40] vs 1% [one of 72], P = .02). Surgery revealed DCIS in one (10%) of 10 lesions that yielded ADH at stereotactic biopsy. Surgery revealed infiltrating carcinoma in one (5%) of 21 lesions that yielded DCIS at stereotactic biopsy. No underestimation occurred when all calcifications were removed. CONCLUSION: Stereotactic, 11-gauge, directional, vacuum-assisted biopsy resulted in successful calcification retrieval in 106 (95%) of 112 cases. Histologic underestimation was infrequent.