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

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.

MRI of occult breast carcinoma in a high-risk population.

OBJECTIVE: The purpose of this study was to determine the frequency of cancer and the positive predictive value of biopsy in the first screening round of breast MRI in women at high risk of developing breast cancer. MATERIALS AND METHODS: Retrospective review was performed of the records of 367 consecutive women at high risk of developing breast cancer who had normal findings on mammography and their first breast MRI screening examination during a 2-year period. The frequency of recommending biopsy at the first screening MRI study and the biopsy results were reviewed. RESULTS: Biopsy was recommended in 64 women (17%). Biopsy revealed cancer that was occult on mammography and physical examination in 14 (24%) of 59 women who had biopsy and in 14 (4%) of 367 women who underwent breast MRI screening. Histologic findings in 14 women with cancer were ductal carcinoma in situ in eight (57%) and infiltrating carcinoma in six (43%). The median size of infiltrating carcinoma was 0.4 cm (range, 0.1-1.2 cm). Two patients had nodes that were positive for cancer. Biopsy revealed high-risk lesions (atypical ductal hyperplasia, atypical lobular hyperplasia, lobular carcinoma in situ, or radial scar) in 13 (4%) of 367 women and other benign findings in 32 (9%) of 367 women who had MRI screening. CONCLUSION: Among women at high risk of developing breast cancer, breast MRI led to a recommendation of biopsy in 17%. Cancer was found in 24% of women who underwent biopsy and in 4% of women who had breast MRI screening. More than half the MRI-detected cancers were ductal carcinoma in situ.

Ductal enhancement on MR imaging of the breast.

OBJECTIVE: The purpose of this study was to determine the prevalence and positive predictive value of ductal enhancement among MR imaging-detected breast lesions that had biopsy and to assess the histologic findings associated with ductal enhancement. MATERIALS AND METHODS: Retrospective review was performed of 427 nonpalpable, mammographically occult lesions that had MR imaging-guided needle localization and surgical biopsy. Lesions were reviewed by one radiologist who was unaware of the histologic outcomes and were classified according to a standardized lexicon. MR imaging and histologic findings of ductal enhancing lesions were reviewed. RESULTS: Ductal enhancement accounted for 88 (21%) of 427 lesions and 88 (59%) of 150 nonmass lesions. Histologic finding in these 88 lesions were ductal carcinoma in situ (DCIS) in 18 (20%); infiltrating carcinoma in five (6%), including three with DCIS; lobular carcinoma in situ (LCIS) in nine (10%); atypical ductal hyperplasia in eight (9%); and benign in 48 (55%). Among the 48 benign lesions, the dominant histologic findings were fibrocystic change (n = 16); ductal hyperplasia (n = 8); fibrosis (n = 8); postbiopsy change (n = 5); benign breast tissue (n = 3); sclerosing adenosis (n = 2); and single cases of fibroadenoma, fibroadenomatoid change, lymph node, mastitis, papilloma, and radial scar. Factors associated with a trend toward a higher frequency of carcinoma included clumped enhancement (p = 0.05) and synchronous ipsilateral cancer (p = 0.07). CONCLUSION: Ductal enhancement accounted for 21% of MR imaging-detected lesions that had biopsy and had a positive predictive value of 26%. Differential diagnosis of ductal enhancement includes carcinoma (usually DCIS); atypical ductal hyperplasia; LCIS; and benign findings such as fibrocystic change, ductal hyperplasia, and fibrosis.

Probably benign lesions at breast magnetic resonance imaging: preliminary experience in high-risk women.

BACKGROUND: 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. METHODS: The authors performed a retrospective review of the records of 367 asymptomatic women with normal mammograms who had a high risk of developing breast cancer and whose first breast MR imaging screening examinations occurred during a 2-year period. The number of "probably benign" interpretations was determined, and follow-up data were obtained. RESULTS: A "probably benign" interpretation was given to 89 (24%) of 367 women. Follow-up MR imaging was performed for 70 (79%) of 89 women, with a median follow-up time of 11 months (range, 1-24 months). Twenty women subsequently underwent biopsy at a median of 9 months (range, 1-18 months) after MR imaging, due to progression on follow-up MR imaging (n=14) or for other reasons (n=6). Malignancies were found in 9 women, constituting 45% of the 20 women who underwent biopsy and 10% of the 89 women with probably benign lesions. In 6 of the 9 women who developed malignant disease (7% of the 89 women in the study), the malignancy was detected by follow-up MR imaging of an area that previously was interpreted as probably benign. Tumor histology was ductal carcinoma in situ (DCIS) in five patients and infiltrating ductal carcinoma in four. CONCLUSIONS: A "probably benign" interpretation was given to 24% of high-risk women at their first breast MR imaging screening examination. In 7-10% of women with "probably benign" interpretations, malignant disease subsequently developed in an area initially judged to be probably benign; of these malignancies, more than half were DCIS, and more than half were detected by MR imaging only.

Breast lesions detected with MR imaging: utility and histopathologic importance of identification with US.

PURPOSE: To determine the utility and histopathologic importance of ultrasonographic (US) depiction of breast lesions detected with magnetic resonance (MR) imaging. MATERIALS AND METHODS: Retrospective review was performed of 654 consecutive breast MR examinations performed from November 1999 to February 2001. This yielded 64 patients with 93 suspicious, nonpalpable, mammographically occult lesions evident on MR images and recommended for biopsy, for which directed US assessment was performed. Images, pathologic records, and medical records of these patients were reviewed for imaging findings, patient demographics, and histopathologic findings from subsequent biopsy. Statistical analysis was performed with the Fisher exact test. RESULTS: The median size of MR abnormalities was 0.9 cm (range, 0.3-5.0 cm). The pattern of enhancement was a focal mass in 76 (82%) lesions and nonmass in 17 (18%). A US correlate was identified in 21 (23%) lesions detected with MR--19 (25%) of 76 focal mass and two (11%) of 17 nonmass lesions. Carcinoma was found in nine (43%) of these lesions, of which seven (78%) were invasive carcinoma and two (22%) were ductal carcinoma in situ (DCIS). Among the lesions without a US correlate, 10 (14%) yielded carcinoma, of which five (50%) were invasive carcinoma and five (50%) were DCIS. The frequency of cancer was significantly higher for lesions that were detected with MR imaging and had a US correlate than for those that did not have a US correlate (43% vs 14%, P =.01). Overall, 19 (20%) lesions detected with MR imaging and examined with US yielded carcinoma at biopsy, and nine (47%) malignant lesions were seen on US images. US depicted seven (58%) of 12 invasive cancers and two (29%) of seven instances of DCIS. CONCLUSION: The likelihood of carcinoma was significantly higher among lesions with a US correlate (43% carcinoma) than lesions without a US correlate (14% carcinoma).

MR imaging of the ipsilateral breast in women with percutaneously proven breast cancer.

OBJECTIVE: The purpose of this study was to review MR imaging findings in the ipsilateral breast in women with percutaneously proven breast cancer. MATERIALS AND METHODS: Retrospective review was performed of records of 70 consecutive women with percutaneously proven unilateral breast cancer who were considered candidates for breast conservation surgery and who had preoperative MR imaging of the ipsilateral breast. MR images and medical records were reviewed. RESULTS: MR imaging identified mammographically and clinically occult cancer other than the index lesion in the ipsilateral breast in 19 women (27%), including infiltrating cancer in 11 women (16%) and ductal carcinoma in situ in eight women (11%). These additional sites of cancer were in the same quadrant as the index cancer in 14 women (20%), in a different quadrant in three women (4%), and in both the same and different quadrants in two women (3%). Additional sites of cancer were more likely in women with, rather than in those without, a family history of breast cancer (42% vs 14%, p < 0.02) and in women whose index cancer was infiltrating lobular rather than other histologies (55% vs 22%, p < 0.06). In 17 women (24%), MR imaging detected ipsilateral lesions that were benign. Changes due to prior percutaneous biopsy were infrequently observed on MR images and included a clip in 12 women (17%) and a small hematoma in two women (3%). CONCLUSION: MR imaging identified additional sites of ipsilateral cancer in 27% of women with percutaneously proven breast cancer. The yield was highest in women with a family history of breast cancer or infiltrating lobular histology in the index cancer. Change after biopsy was infrequent and did not interfere with the MR imaging interpretation.

MR imaging findings in the contralateral breast of women with recently diagnosed breast cancer.

OBJECTIVE: The purpose of this study was to determine the frequency and positive predictive value of biopsy performed on the basis of MR imaging findings in the contralateral breast in women with recently diagnosed breast cancer. MATERIALS AND METHODS: We performed a retrospective review of records of 1336 consecutive breast MR imaging examinations over a 2-year period. Of these examinations, 223 imaged the asymptomatic, mammographically normal contralateral breast in women whose breast cancer was diagnosed within 6 months preceding MR imaging. Records of these 223 examinations were reviewed to determine the frequency of recommending contralateral breast biopsy and the biopsy results. RESULTS: Contralateral breast biopsy was recommended in 72 (32%) of 223 women and performed in 61 women. Cancer occult to mammography and physical examination was detected by MR imaging in 12 women, constituting 20% (12/61) of women who underwent contralateral biopsy and 5% (12/223) of women who underwent contralateral breast MR imaging. Among these 12 cancers, six (50%) were ductal carcinoma in situ (DCIS) and six (50%) were infiltrating carcinoma. The median size of infiltrating carcinoma was 0.5 cm (range, 0.1-1.0 cm). Contralateral biopsy revealed benign (n = 31) or high-risk (n = 18) lesions in 49 women, constituting 80% (49/61) of women who underwent contralateral biopsy and 22% (49/223) of women who underwent contralateral MR imaging. CONCLUSION: In women with recently diagnosed breast cancer, MR imaging of the contralateral breast led to a biopsy recommendation in 32%. Cancer was found in 20% of women who underwent contralateral breast biopsy and in 5% of women who underwent contralateral breast MR imaging.

To excise or to sample the mammographic target: what is the goal of stereotactic 11-gauge vacuum-assisted breast biopsy?

OBJECTIVE: This study was undertaken to determine whether complete percutaneous excision rather than sampling of the mammographic target conveys any significant advantage or disadvantage at stereotactic 11-gauge vacuum-assisted biopsy. MATERIALS AND METHODS: A retrospective review was performed of 788 consecutive solitary lesions in which the mammographic target was excised (n = 466) or sampled (n = 322) at stereotactic 11-gauge vacuum-assisted biopsy. Medical records and histologic findings were reviewed to determine the frequency of sparing surgery, discordance, histologic underestimation, rebiopsy, complete histologic removal of cancer, and complications. Statistical comparisons were made using the Fisher's exact test. RESULTS: Complete excision rather than sampling of the mammographic target was associated with a significantly lower frequency of discordance (1/466, 0.2% vs 8/322, 2.5%; p = 0.004) and a trend toward fewer ductal carcinoma in situ underestimates (4/59, 6.8% vs 12/60, 20.0%; p = 0.07). Complete histologic removal of cancer was significantly more likely if the mammographic target was excised rather than sampled (19/91, 20.9% vs 7/106, 6.6%; p = 0.006); however, among 91 cancers in which the mammographic target was excised, surgery revealed residual cancer in 72 (79.1%). Complete excision rather than sampling of the mammographic target yielded no significant differences in the frequency of sparing surgery, atypical ductal hyperplasia underestimates, rebiopsy, or complications. CONCLUSION: Complete excision rather than sampling of the mammographic target was associated with lower frequencies of discordance and ductal carcinoma in situ underestimation but had no other advantage or disadvantage. Among cancers in which the mammographic target was excised, surgery revealed residual cancer in almost 80%.

Histologic heterogeneity of masses at percutaneous breast biopsy.

The purpose of this study was to determine whether different histologic findings are obtained from different areas of breast masses seen on mammography when targeted on stereotactic breast biopsy. Twenty-one masses (mean size, 1.8 cm; range, 0.7-5.5 cm) underwent stereotactic biopsy using a 14-gauge directional vacuum-assisted biopsy probe (Mammotome, Biopsys/Ethicon Endo-Surgery, Cincinnati, OH). The central and peripheral areas of the mass were targeted and biopsied separately, and histologic findings from the targeted center and periphery were compared. Six of 21 masses (29%) were heterogeneous, yielding different histologic results from the targeted center and periphery. In 4 heterogeneous masses, which constituted 4 of 21 masses (19%) in this study, surgical biopsy was recommended on the basis of findings obtained from only the center (n = 2) or the periphery (n = 2). Stereotactic biopsy findings in these 4 masses were atypia in 3 and radial scar in 1; none of these 4 masses had carcinoma at surgery. In all 4 masses that proved to be malignant, the diagnosis of carcinoma was made in specimens obtained from both the targeted center and the periphery of the mass. Breast masses can be heterogeneous, yielding different histologic findings from different areas of the mass. Our data suggest that sampling part but not all of a mass may miss certain histologic components of the mass, but should not result in a failure to diagnose carcinoma.

Breast lesions detected on MR imaging: features and positive predictive value.

OBJECTIVE: The purpose of this study was to analyze features of breast lesions detected on MR imaging that had subsequent biopsy and to determine the positive predictive value (PPV) of these features. MATERIALS AND METHODS: Retrospective review was performed of 100 consecutive solitary MR imaging-detected breast lesions that had MR imaging-guided needle localization and surgical excision. We described lesions, using terms found in a proposed breast MR imaging lexicon. Histologic findings were reviewed. RESULTS: Carcinoma was identified in 25 lesions (25%), including ductal carcinoma in situ (DCIS) in 13 (52%) and infiltrating carcinoma in 12 (48%). Carcinoma was found in 15 (25%) of 60 masses versus 10 (25%) of 40 nonmass lesions; most malignant masses (73%) were infiltrating carcinoma, whereas most malignant nonmass lesions (90%) were DCIS. The features with the highest PPV were spiculated margin (80% carcinoma), rim enhancement (40% carcinoma), and irregular shape (32% carcinoma) for mass lesions and segmental (67% carcinoma) or clumped linear and ductal enhancement (31% carcinoma) for nonmass lesions. Visually assessed kinetic patterns were not significant predictors of carcinoma, but washout was present in 70% of infiltrating carcinomas versus 9% of DCIS lesions (p < 0.01). Carcinoma was present in 17 (19%) of 88 lesions classified as suspicious versus eight (67%) of 12 lesions classified as highly suggestive of malignancy (p = 0.001). CONCLUSION: Among MR imaging-detected breast lesions referred for biopsy, carcinoma was found in 25%, of which half were DCIS. Features with the highest PPV were spiculated margin, rim enhancement, and irregular shape for mass lesions and segmental or clumped linear and ductal enhancement for nonmass lesions. Final assessment categories were significant predictors of carcinoma.

Preoperative MR imaging-guided needle localization of breast lesions.

OBJECTIVE: MR imaging of the breast can depict cancer that is occult on mammography and at physical examination. Our study was undertaken to determine the ease of performance and the outcome of MR imaging-guided needle localization and surgical excision of breast lesions. MATERIALS AND METHODS: Retrospective review revealed 101 consecutive breast lesions that had preoperative MR imaging-guided needle localization with commercially available equipment, including a 1.5-T magnet with a breast surface coil, a dedicated biopsy compression device, and MR imaging-compatible hookwires. Imaging studies and medical records were reviewed. RESULTS: Histologic findings in these 101 lesions were carcinoma in 31 (30.7%), high-risk lesions (atypical ductal hyperplasia or lobular carcinoma in situ) in nine (8.9%), and benign lesions in 61 (60.4%). Fifteen (48.4%) of 31 carcinomas were ductal carcinoma in situ, and 16 (51.6%) were infiltrating carcinoma (size range, 0.1-2.0 cm; median, 1.2 cm). Carcinoma was found in 16 (45.7%) of 35 lesions detected in women with synchronous cancer, 10 (32.3%) of 31 lesions detected on MR imaging for problem solving, and five (14.3%) of 35 lesions detected on MR screening. The time range to perform MR imaging-guided localization was 15-59 min (median time, 31 min). Complications encountered in three cases were retained wire fragments in two and breakage of the wire tip in one. CONCLUSION: MR imaging-guided needle localization can be performed quickly and safely with commercially available equipment. The positive predictive value of MR imaging-guided needle localization (30.7%) was comparable to that reported for mammographically guided needle localization and was highest in women with synchronous breast cancer.

One operation after percutaneous diagnosis of nonpalpable breast cancer: frequency and associated factors.

OBJECTIVE: The purpose of this study was to determine the frequency of and factors associated with performing one therapeutic operation after percutaneous diagnosis of nonpalpable breast cancer. MATERIALS AND METHODS: Retrospective review was performed of records of 350 consecutive women who had therapeutic surgery after percutaneous imaging-guided core biopsy diagnosis of nonpalpable breast cancer. Records were reviewed to determine the frequency of performing one operation and associated factors. Statistical analysis was performed. RESULTS: One operation was performed in 283 (80.9%) of 350 women, including 106 (95.5%) of 111 women who had mastectomy and 177 (74.1%) of 239 women who had breast conserving surgery. At bivariate analysis, one operation was significantly more likely in women who had no underestimation (p < 0.001), mastectomy rather than breast conservation (p < 0.001), axillary dissection during the first operation (p < 0.001), percutaneous diagnosis of infiltrating carcinoma (p = 0.001), or mammographic mass (p = 0.006). At multivariate analysis, one operation was significantly more likely if underestimation was absent (odds ratio [OR] = 10.1, 95% confidence interval [CI] = 4.2-24.7) or if mastectomy was performed (OR = 8.7, 95% CI = 3.2-23.5); for women who had breast-conserving surgery, one operation was significantly more likely if underestimation was absent (OR = 11.4, 95% CI = 3.9-33.2) or if a mammographic mass was present (OR = 2.4, 95% CI = 1.3-4.6). CONCLUSION: One operation was performed in 80.9% of women with percutaneously proven nonpalpable breast cancer, including 74.1% of women who had breast-conserving surgery and 95.5% of women who had mastectomy. Among women who had breast conservation, one operation was significantly more likely if histologic underestimation was absent or if a mammographic mass was present.