Architectural and dynamic features are important in breast MR imaging interpretation. Multivariate models involving feature assessment have a diagnostic accuracy superior to that of qualitative characterization of the dynamic enhancement pattern.

AMMOGRAPHY IS THE PRImary imaging modality used to detect clinically occult breast cancer. However, mammography has limitations in both sensitivity and specificity that have led to exploration of other imaging techniques. Magnetic resonance imaging (MRI) has been evaluated for breast imaging because of its value for assessing soft tissues of the body. Breast MRI is performed before and after injection of a gadoliniumbased contrast agent. 1,2 Additional lesions seen by MRI that are not visible on the mammogram have been reported to be present in between 27% and 37% of patients. 3,4 The use of MRI to evaluate women with mammographically or clinically suspicious breast lesions who are undergoing biopsy has shown high potential, with the reported sensitivities of MRI for breast cancer from larger single center studies ranging from 88% to 95%. 5-12 Thus, there has been considerable enthusiasm for breast MRI and use of the procedure for Medicare patients increased almost 3-fold between 2001 (3440 examinations) and 2003 (10 115 examinations). 13 However, the reported specificity of MRI is variable, ranging from 30% to For editorial comment see p 2779.

Core needle biopsy is the preferred technique for evaluating breast masses and abnormal mammographic findings. The frequency of detection of noninvasive lobular lesions by core needle biopsy is increasing. Historically, the diagnosis of lobular carcinoma in situ has been considered a risk factor for the development of invasive carcinoma, and treatment has consisted of careful clinical follow-up with or without chemopreventive therapeutic agents such as tamoxifen citrate. We retrospectively reviewed core needle biopsy material with the primary diagnoses of lobular carcinoma in situ, atypical lobular hyperplasia, and lobular neoplasia in conjunction with clinical and radiographic findings to make recommendations as to when excision may be merited. We searched our database for core needle biopsy cases with lobular carcinoma in situ, atypical lobular hyperplasia, and lobular neoplasia as the primary diagnosis. Microcalcifications had been sampled with a stereotactically guided, 11 G Mammotome biopsy device, and masses had been sampled with an ultrasound guided, 18 G core needle. Glass slides were reviewed and histological parameters assessed. Mammographic findings were reviewed, and clinical information was obtained from the medical record. When available, excisional biopsy material was reviewed. The 2337 breast core needle biopsies performed from January 1995 to December 2001 included 35 (1.5%) with classic lobular carcinoma in situ (14), lobular neoplasia (4), and atypical lobular hyperplasia (17) as the primary diagnosis. Twelve of these 35 cases (34%) had histological evidence of microcalcifications directly associated with the lobular carcinoma in situ, lobular neoplasia, atypical lobular hyperplasia. Radiologic review revealed 21 calcifications, 6 ultrasonographic masses, and 8 mammographic masses and/or architectural distortions. Excisional biopsy had been performed in 17 cases (49%). In six cases diagnosed as in situ on core needle biopsy, excisional biopsy revealed invasive carcinoma. All of these patients had radiographically detectable masses. Eleven cases had excisional biopsies that showed histology similar to that of the core needle biopsies. The most important predictor of invasive carcinoma on excision was a synchronous mass lesion. Lobular carcinoma in situ involving adenosis and lobular carcinoma in situ with pagetoid spread on core needle biopsies did not show a histologically more aggressive lesion on excision and, therefore, may not require additional surgery. Histologically identified calcifications were associated with lobular lesions 34% of the time; however, their presence inside an in situ lobular lesion did not portend worse pathology on re-excision and should not be a criterion for excision. Based on these findings, we recommend excisional biopsy of lobular carcinoma in situ, atypical lobular hyperplasia or lobular neoplasia only when it is associated with a synchronous mass lesion. The increased use of screening mammography has resulted in an increasing number of image-guided breast biop...

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In 824 patients who underwent directional vacuum-assisted biopsies (DVABs) of breast microcalcifications, 61 (7.4%) showed atypical ductal hyperplasia (ADH). The 42 who subsequently underwent excision were the subjects of this study. Cases were evaluated for the mammographic characteristics of the lesion, the percentage of lesion removed according to mammography, and histologic findings (including number of large ducts and/or terminal duct-lobular units involved with ADH) in DVAB specimens. Pathologic findings in the surgical specimens in the area of the biopsy site also were recorded. In the DVAB specimens, ADH was confined to an average of 1.5 large ducts or lobular units and was associated with microcalcifications in all of the patients. Surgical specimens showed ADH in 15 cases, no residual lesion in 24 cases, and ductal carcinoma in situ in 3 cases. We found that microcalcifications that contain ADH in less than 3 lobules or ducts and/or that are removed completely by DVAB do not reveal higher-risk lesions on excision; thus, removal is unnecessary. When assessing microcalcifications with ADH, clinicians should consider the percentage of microcalcifications removed by DVAB and the extent of lobular involvement to better assess the need for excision.