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.

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.

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.

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.

Percutaneous removal of malignant mammographic lesions at stereotactic vacuum-assisted biopsy.

PURPOSE: To determine whether complete percutaneous removal of a malignant lesion detected at mammography ensures complete excision of the carcinoma histopathologically. MATERIALS AND METHODS: A retrospective review was performed of 135 lesions in which stereotactic biopsy was performed with a directional, vacuum biopsy instrument and an 11-gauge probe followed by mammography. Carcinoma was diagnosed at stereotactic biopsy in 51 (38%) lesions. In 15 (29%) carcinomas, the lesion seen at mammography was removed at stereotactic biopsy. Surgical findings were available for correlation with biopsy and imaging findings in all 15 cases. Mammographic and histopathologic findings were reviewed. RESULTS: Mammographic findings were calcifications in 11 lesions and a mass in four lesions. The median lesion size was 0.7 cm (range, 0.2-1.4 cm), and the median number of biopsy specimens was 15 (range, 10-22 specimens). Histopathologic findings at stereotactic biopsy were ductal carcinoma in situ in 12 lesions and infiltrating ductal carcinoma in three. Surgery revealed residual carcinoma in 11 (73%) of 15 lesions, including all three infiltrating ductal carcinomas and eight of 12 ductal carcinoma in situ lesions. CONCLUSION: Complete removal of the mammographic lesion does not ensure complete excision of the carcinoma.

Clip placement after stereotactic vacuum-assisted breast biopsy.

PURPOSE: To assess accuracy and usefulness of placement of a localizing clip after stereotactic, vacuum-assisted breast biopsy. MATERIALS AND METHODS: Retrospective review was performed of 57 lesions that underwent placement of a localizing clip after stereotactic vacuum-assisted biopsy with an 11-gauge (n = 42) or 14-gauge (n = 15) probe. The clip was placed when images obtained after stereotactic biopsy suggested that the lesion seen at mammography was removed. Coordinates of the clip on stereotactic images obtained after placement were compared with lesion coordinates determined before biopsy. Surgery was performed in 25 cases. Mammographic and histopathologic findings were reviewed. RESULTS: The distance from clip to lesion site was less than 1 cm in 40 (95%) of 42 lesions that underwent clip placement with the 11-gauge probe versus 11 (73%) of 15 lesions that underwent clip placement after 14-gauge biopsy (P < .04). The biopsy site was identified in the surgical specimen in 19 (100%) lesions with clips after 11-gauge biopsy and five (83%) of six lesions with clips after 14-gauge biopsy. No complications occurred. CONCLUSION: A localizing clip can be placed in proximity to the stereotactic biopsy site through an 11-gauge probe. Clip placement can enable accurate localization for surgical excision.

MR imaging of the breast in patients with occult primary breast carcinoma.

PURPOSE: To evaluate the utility of contrast material-enhanced magnetic resonance (MR) imaging of the breast for localization of the site of primary breast carcinoma in patients with isolated ipsilateral axillary metastasis, without other focal findings at physical examination or mammography. MATERIALS AND METHODS: Twelve women with biopsy-proved metastatic adenocarcinoma to axillary lymph nodes and occult primary tumor underwent MR imaging at 1.5 T with a three-dimensional spoiled gradient-echo pulse sequence before and after administration of gadopentetate dimeglumine. Enhancing areas were correlated with histopathologic findings at mastectomy (n = 8) or breast-conserving treatment (n = 4). RESULTS: In nine (75%) of the 12 patients, enhancement was seen on MR images that represented the site of the primary tumor at surgery. Eight had focal masses, and one had an area of regional enhancement. Two patients had negative MR findings, and no tumor was found at mastectomy. One patient with regional enhancement on MR images had no corresponding tumor at surgery. CONCLUSION: Breast MR imaging enables identification of the site of primary tumor in most patients suspected of having occult primary breast cancer, and MR findings can influence surgical treatment.

Stereotactic core biopsy of calcifications highly suggestive of malignancy.

PURPOSE: To assess stereotactic core biopsy for evaluation of Breast Imaging Reporting and Data System (BI-RADS) category 5 calcifications (highly suggestive of malignancy). MATERIALS AND METHODS: Retrospective review of mammograms revealed 31 women (aged 34-86 years) with BI-RADS category 5 calcifications who underwent 14-gauge stereotactic core biopsy with an automated gun. Records were reviewed to determine the frequency with which stereotactic core biopsy obviated a surgical procedure. Cost savings were based on Medicare estimates of $472 for stereotactic core biopsy and $1,335 for surgical biopsy. RESULTS: Of 31 patients, stereotactic core biopsy revealed carcinoma in 19 (61%), atypical ductal hyperplasia (ADH) in eight (26%), and benign findings discordant with mammographic results in four (13%). Surgical biopsy was recommended for the 12 patients with ADH or benign but discordant core biopsy diagnoses. Of the 19 patients with carcinoma at stereotactic core biopsy, two chose to undergo a second biopsy surgically, two had small foci of ductal carcinoma in situ (DCIS) that would have been fully excised with surgical biopsy, one with DCIS at stereotactic core biopsy underwent axillary dissection after invasion was found at surgery, and one underwent excision but had tumor at lumpectomy margins. Thirteen (42%) of 31 patients were spared a surgical procedure, saving $100 per patient. CONCLUSION: Stereotactic core biopsy with an automated gun obviated a surgical procedure in 42% of patients with BI-RADS category 5 calcifications, resulting in modest cost savings in this group.

Mammographic findings after stereotactic 14-gauge vacuum biopsy.

PURPOSE: To evaluate mammographic findings after stereotactic 14-gauge vacuum biopsy. MATERIALS AND METHODS: Retrospective review was performed of results at stereotactic 14-gauge vacuum biopsy in 108 lesions in 100 women. The median number of specimens obtained per lesion was 12 (mean, 14; range, 1-50). In all cases, mammography was performed immediately after vacuum biopsy. Pre- and postbiopsy mammograms were reviewed. RESULTS: Postbiopsy mammograms depicted air at the biopsy site in 78 (72%) of 108 lesions and hematoma in 65 (60%) of 108 lesions. Of 55 lesions depicted as calcifications, postbiopsy mammograms depicted a decrease in the number of calcifications in 45 (82%), including nine cases in which all calcifications were removed. No residual lesion was identified on postbiopsy mammograms in 14 (13%) of 108 lesions; 11 (58%) of 19 mammographic lesions that measured 0.5 cm or less in maximal dimension were completely removed. Nineteen patients underwent a needle localization procedure, at a median 14 days (range, 6-51 days) after vacuum biopsy. In one patient a hematoma was depicted at mammography 10 days after biopsy; in the remaining 18 (95%) patients, mammograms obtained during needle localization depicted no hematoma or air. CONCLUSION: Air and hematoma were often present on mammograms immediately after stereotactic vacuum biopsy, but these changes resolved rapidly. Stereotactic vacuum biopsy provided wide sampling of calcifications and allowed complete removal of the mammographic lesion in some cases.

Analysis of cancers not diagnosed at stereotactic core breast biopsy.

PURPOSE: To evaluate the mammographic and histopathologic features of carcinomas not diagnosed at stereotactic core biopsy. MATERIALS AND METHODS: A retrospective review revealed 144 surgically confirmed carcinomas preoperatively sampled with stereotactic core biopsy. Diagnosis at stereotactic core biopsy was carcinoma in 116 (81%) lesions, atypical hyperplasia in 21 (15%), and benign findings discordant with those from mammography in seven (5%). Mammographic and histopathologic findings in the latter 28 cases were reviewed. RESULTS: Prompt repeat biopsy was recommended in all 28 cases. The frequency with which a cancer yielded atypical hyperplasia at stereotactic core biopsy was higher for calcifications than masses (30% vs 5%, P < .0001), ductal carcinoma in situ (DCIS) than infiltrating carcinoma (33% vs 7%, P = .0002), and noncomedo than comedo DCIS (60% vs 9%, P = .0008). No significant difference was observed in the likelihood of benign core biopsy findings without atypia in malignant calcifications versus masses (7% vs 3%, P = .43), DCIS versus infiltrating carcinoma (7% vs 4%, P = .43), or noncomedo versus comedo DCIS (0% vs 9%, P = .49). CONCLUSION: The likelihood of not diagnosing carcinoma was highest for calcifications and for noncomedo DCIS. Discordance in mammographic and histopathologic findings or the presence of atypical hyperplasia may enable the radiologist to identify missed or underestimated carcinomas prospectively and avoid a delay in diagnosis.